福州市高中毕业班数学质量检测答案
- 格式:docx
- 大小:58.13 KB
- 文档页数:5
2023-2024学年第一学期福州市四校教学联盟1月期末学业联考高一数学试卷考试范围:必修一命题教师:审核教师:考试时间:1月3日完卷时间:120分钟满分:150分一、单项选择题:本大题共8小题,每小题5分,满分40分。
在每小题所给出的四个选项中,只有一个选项是符合题意的。
1.集合A={x∣−2<x≤2},B={−2,−1,0,1},则A∩B=A.{−1,1,2}B.{−2,−1,0,1}C.{−1,0,1}D.{−2,−1,0,1,2}2.若a>b>0,c>d,则下列结论正确的是3.函数y=−|ln(x−1)|的图象大致是A.B.C.D.4.命题p:α是第二象限角或第三象限角,命题q:cosα<0,则p是q的A.充要条件B.必要不充分条件C.充分不必要条件D.既不充分也不必要条件A.110%B.120%C.130%D.140%7.命题“对∀x∈[1,2],ax2−x+a>0”为真命题的一个充分不必要条件可以是8.已知f(x)=ax2−1是定义在R上的函数,若对于任意−3≤x1<x2≤−1,都有f(x1)−f(x2)<2,则实数x1−x2a的取值范围是二、多项选择题:本大题共4小题,每小题5分,满分20分。
在每小题所给出的四个选项中,有多个选项是符合题意的。
9.下列大小关系正确的是A.20.3<20.4B.30.2<40.2C.log23<log48D.log23>log32 10.设正实数x,y满足x+y=2,则下列说法正确的是A.当k>1,有1个零点B.当k>1时,有3个零点C.当k<0时,有9个零点D.当k=−4时,有7个零点三、填空题:本大题共4小题,每小题5分,满分20分。
13.已知扇形的圆心角是2rad,其周长为6cm,则扇形的面积为cm2.四、解答题:本大题共6小题,满分70分。
除第17小题10分以外,每小题12分。
福建省福州市2024届高三上学期第一次质量检测数学试题含答案本文为福建省福州市2024届高三上学期第一次质量检测数学试题及答案的解析。
为了方便阅读,我们将试题分为多个小题,并提供相应的解答。
第一大题:选择题1. 若函数 f(x) 的定义域为实数集 R,且关于 x 的方程 f(x) = a 有且仅有一个实根,则实数 a 的取值范围是?解答:由于函数 f(x) 只有一个实根,所以必然存在一个实数 a,使得 f(a) = 0。
因此,实数 a 在实数集 R 中的取值范围为全体实数。
2. 已知函数 f(x) = ax^2 + bx + c 在区间 [2, 4] 上的最大值为 5,最小值为 1,且在区间 (2, 4) 上函数的图象单调递减,则函数 f(x) 是递增函数的区间为?解答:根据题意,函数 f(x) 在区间 (2, 4) 上为递减函数。
由于 f(x) 是一个二次函数,其图象开口方向由二次项系数 a 的正负决定。
由于函数在区间 [2, 4] 上的最大值为 5,最小值为 1,而图象单调递减,则函数必然在区间 (2, 4) 上为递减函数。
因此,函数 f(x) 是递增函数的区间为空集。
...第二大题:解答题1. 给定一个等差数列 {an},已知 a1 = 2,d = 3。
求该等差数列的通项公式。
解答:设等差数列的通项公式为 an = a1 + (n-1)d。
代入已知条件 a1 = 2,d = 3,得到 an = 2 + (n-1)3。
因此,该等差数列的通项公式为 an = 3n - 1。
2. 已知函数 f(x) 的导函数为 f'(x) = 2x + 1,且 f(1) = 3。
求函数 f(x) 在点 x = 2 处的函数值。
解答:根据题意,函数 f(x) 的导函数为 f'(x) = 2x + 1。
对导函数进行积分,得到 f(x) = x^2 + x + C,其中 C 为常数。
由于 f(1) = 3,代入得到 1^2 + 1 + C = 3,解得 C = 1。
2023年福州市普通高中毕业班质量检测数学试卷一、单项选择题:本题共8小题,每小题5分,共40分.在每小题给出的四个选项中,只有一项是符合题目要求的.1.已知集合{}12A x x =-≤,{|2x B x =,则A B =( )A .112x x ⎧⎫-⎨⎬⎩⎭≤≤B.{|1x x -≤ C .12x x ⎧⎫⎨⎬⎩⎭≤ D .{|3}x x ≤1.【答案】D【解析】因为{}12{|13}A x x x x =-=-≤≤≤,1{|22x B x x x ⎧⎫==⎨⎬⎩⎭≤≤,所以{|3}x A B x = ≤.故选:D2.已知(1i)24i z +=-,则z = ( )A .2 BC .4D .102.【答案】B【解析】因为(1i)24i z +=-,所以24i1i z -=+,所以24i 1i z -===+. 3.若二项式2213nx x ⎛⎫+ ⎪⎝⎭展开式中存在常数项,则正整数n 可以是( )A .3B .5C .6D .73.【答案】C【解析】二项式2213n x x ⎛⎫+ ⎪⎝⎭展开式的通项为224121C (3)3C rr n r n r r n r r n n T x xx ---+⎛⎫== ⎪⎝⎭, 令240n r -=,解得:2n r =,又因为0r n ≤≤且r 为整数,所以n 为2的倍数,所以6n =,故选:C .4.为培养学生“爱读书、读好书、普读书”的良好习惯,某校创建了人文社科类、文学类、自然科学类三个读书社团.甲、乙两位同学各自参加其中一个社团,每位同学参加各个社团的可能性相同,则这两位同学恰好参加同一个社团的概率为 ( ) A .13B .12C .23D .344.【答案】A【解析】甲、乙两位同学各自随机选择一个社团,共有9种情况,这两位同学恰好参加同一个社团,共有3种情况,故这两位同学恰好参加同一个社团的概率3193P ==.故选:A 5.已知2b a = ,若a 与b 的夹角为120︒,则2a b - 在b上的投影向量为( )A .3b -B .32b -C .12b - D .3b5.【答案】B【解析】2223(2)22cos1202a b b a b b a b b b -⋅=⋅-=⋅⋅︒-=- ,2a b ∴- 在b 上的投影向量为23(2)322b a b b b b b b b b b--⋅⋅=⋅=-.故选:B 6.已知221:(2)(3)4O x y -+-= ,1O 关于直线210ax y ++=对称的圆记为2O ,点E ,F 分别为1O ,2O 上的动点,EF 长度的最小值为4,则=a( )A .32-或56B .56-或32C .32-或56- D .56或326.【答案】D【解析】由题易知两圆不可能相交或相切,则如图, 当EF 过两圆圆心且与对称轴垂直又接近于对称轴时, EF 长度最小,此时圆心1O 到对称轴的距离为4,4,22(27)16(4)a a +=+,解得32a =或56a =.故选:D7.已知三棱锥-P ABC 的四个顶点都在球O的球面上,PA PB PC AB ====2π3ACB ∠=,则球O 的体积为( ) A .3πB .27π8C .9π2D .9π7.【答案】C 【解析】由PA PB PC ==可知点P 在底面ABC 内的射影为ABC △的外心,所以是圆锥模型,设ABC △外接圆半径为r,则2sinABr ACB===∠, 所以r =2h ==,设外接球半径为R ,则222()R h R r =-+,即22(2)2R R =-+,解得32R =,所以球O 的体积为344279πππ3382V R ==⨯=.故选:C . 8.已知函数()f x ,()g x 的定义域均为R ,(1)f x +是奇函数,且(1)()2f x g x -+=,()(3)2f x g x +-=,则( )A .()f x 为奇函数B .()g x 为奇函数C .201()40k f k ==∑D .201()40k g k ==∑8.【答案】D【解析】因为()(3)2f x g x +-=,所以(3)()2f x g x ++=,又(1)()2f x g x -+=, 则有(3)(1)f x f x +=-,因为(1)f x +是奇函数,所以(1)(1)x x f f =--+,可得(3)(1)f x f x +=-+,即有(2)()f x f x +=-与(4)(2)f x f x +=-+,即(4)()f x f x +=,所以()f x 是周期为4的周期函数,故()g x 也是周期为4的周期函数. 因为()(2)f x f x --=+,所以()()f x f x -=,所以()f x 为偶函数.故A 错误; 由(1)f x +是奇函数,则(1)0f =,所以(3)0f =,又(2)(4)(2)(0)0f f f f +=+=, 所以201()5[(1)(2)(3)(4)]0k f k f f f f -=+++=∑,所以C 选项错误;由(1)0f =得(0)2g =,所以B 选项错误;因为(2)2(5)2(1)2g f f =-=-=,(1)(3)[2(4)][2(6)]4[(4)(2)]4g g f f f f +=-+-=-+=, 所以(0)(1)(2)(3)8g g g g +++=,所以201()5[(0)(1)(2)(3)]40k g k g g g g ==+++=∑,所以D 正确.二、多项选择题:本题共4小题,每小题5分,共20分.在每小题给出的四个选项中,有多项符合题目要求.全部选对的得5分,部分选对的得2分,有选错的得0分.9.已知函数π()2sin 23f x x ⎛⎫=+ ⎪⎝⎭,则 ( )A .()f x 在区间π,02⎡⎤-⎢⎥⎣⎦单调递增 B .()f x 在区间[0,π]有两个零点 C .直线π12x =是曲线()y f x =的对称轴 D .直线2π43y x =+是曲线()y f x =的切线 9.【答案】BCD【解析】对于A ,当π,02x ⎡⎤∈-⎢⎥⎣⎦,则22,333πππx ⎡⎤+∈-⎢⎥⎣⎦,因为sin y x =在2ππ,33⎡⎤-⎢⎥⎣⎦先减后增,所以π,02⎡⎤-⎢⎥⎣⎦不是()f x 的增区间,故错误;对于B ,当[0,π]x ∈时,π72,333x ππ⎡⎤+∈⎢⎥⎣⎦,令π23x π+=或2π,解得3x π=或5π6,所以()f x 在区间[0,π]有两个零点,故正确;对于C ,令π12x =,则ππsin 2sin 132x ⎛⎫+== ⎪⎝⎭,所以直线π12x =是曲线()y f x =的对称轴,故正确;对于D ,由π()2sin 23f x x ⎛⎫=+ ⎪⎝⎭可得π()4cos 23f x x ⎛⎫'=+ ⎪⎝⎭,令π()4cos 243f x x ⎛⎫'=+= ⎪⎝⎭,即π22π,3x k k +=∈Z ,解得ππ,6x k k =-+∈Z ,当0k =时,π6x =-,代入()f x 可得π06f ⎛⎫-= ⎪⎝⎭,所以()f x 在点π,06⎛⎫- ⎪⎝⎭处的切线为π46y x ⎛⎫=+ ⎪⎝⎭,化简得2π43y x =+,故D 正确.故选:BCD10.已知曲线222:1424x y C m +=-,则 ( )A .若m >,则C 是椭圆B .若m <<C 是双曲线 C .当C 是椭圆时,若m 越大,则C 越接近于圆D .当C 是双曲线时,若m 越小,则C 的张口越大 10.【答案】BD【解析】对于A ,2m =满足m >,代入曲线C 中,得22144x y +=,即224x y +=,表示以(0,0)为圆心,半径为2的圆,故A 错误;对于B ,当m <<24240m --<≤,所以24(24)0m -<,故C 是双曲线,故B 正确;对于C ,当C 是椭圆时,2240m ->,且2244m -≠,解得22m >且24m ≠,即m >且2m ≠,所以当m 越接近2时,椭圆C 越接近于圆.所以C 错误.对于D ,当曲线222:1424x y C m +=-为双曲线时,2240m -<,整理成2221442x y m-=-,则2a =,b =,当m 越小,则b =b y x a=的斜率越大,图象的张口就越大,故D 正确.故选:BD .11.在棱长为2的正方体1111ABCD A B C D -中,E ,F 分别为棱BC ,1CC 的中点,P 为线段EF 上的动点,则 ( )A .线段DP 长度的最小值为2B .三棱锥1D A AP -的体积为定值C .平面AEF 截正方体所得截面为梯形D .直线DP 与1AA 所成角的大小可能为π311.【答案】BC【解析】对于A :DE DF == ,EF =,∴当点P 为EF 的中点时,此时DP 长度的最小,最=,A 错;对于B ://EF 平面11AA D D ,∴点P 到平面11AA D D 的距离等于E 到平面11AA D D 的距离,故三棱锥1D A AP -的体积等于三棱锥1P A AD -的体积也等于三棱锥1E A AD -的体积,为114222323⨯⨯⨯⨯=,B 正确;对于C :如图平面AEF 截正方体所得截面为四边形AEFD ,因为11////EF BC AD ,且111122EF BC AD ==,所以四边形AEFD 为梯形,C 正确; 对于D :过点P 作PN BC ⊥于点N ,连接DN ,则PN ⊥平面ABCD , 所以1//PN AA ,则直线DP 与AA 1所成角的大小为DPN ∠或其补角,令EN a =,则PN a =,1CN a =-,DN =,tan DNDPN PN ∴∠===令225211415,0155t a a a a ⎛⎫=-+=-+ ⎪⎝⎭≤≤,01a ≤≤,当0a =时,1DP AA ⊥,当01a <≤,11a ≥,而22521141555t a a a ⎛⎫=-+=-+ ⎪⎝⎭在[1,)+∞上单调递增,所以21451455t ⎛⎫-+= ⎪⎝⎭≥,即tan 2DPN ∠>≥故直线DP 与1AA 所成角的大小不可能为π3,D 错.故选:BC12.若x ,y 满足223x xy y ++=,则 ( )A .2x y +≤B .21x y +-≥C .228x y xy +-≤D .221x y xy +-≥12.【答案】AD【解析】由223x xy y ++=,可得2213324x y y ⎛⎫++= ⎪⎝⎭,令1,2,x y y θθ⎧+=⎪⎪=可得sin 2sin x y θθθ⎧=-⎪⎨=⎪⎩,对于A 、B:22sin 2sin [x y θθθθ+=-+=∈-,故A 正确,B 错误;对于C 、D:22323sin )2sin x y xy xy θθθ+-=-=--⋅23sin 4sin 32(1cos 2)θθθθθ=-+=-+-1542cos 254sin 2[1,9]26πθθθ⎫⎛⎫=-+=-+∈⎪ ⎪⎪⎝⎭⎝⎭,故C 错误,D 正确.故选:AD . 三、填空题:本大题共4小题,每小题5分,共20分.把答案填在题中的横线上.13.若3cos 5α=-,α是第三象限角,则tan 2α=___________. 13.【答案】247-【解析】因为3cos 5α=-,且α是第三象限角,所以4sin 5α==-,则sin 4tan cos 3ααα==, 所以282tan 243tan 2161tan 719ααα===---,故答案为:247-. 14.利率变化是影响某金融产品价格的重要因素经分析师分析,最近利率下调的概率为60%,利率不变的概率为40%.根据经验,在利率下调的情况下该金融产品价格上涨的概率为80%,在利率不变的情况下该金融产品价格上涨的概率为40%.则该金融产品价格上涨的概率为__________. 14.【答案】64%##1625##0.64 【解析】由题意可知金融产品价格上涨的概率为:60%80%40%40%064.⨯+⨯=,故答案为:0.64 15.已知曲线32()362f x x x x =-++在点P 处的切线与在点Q 处的切线平行,若点P 的纵坐标为1,则点Q 的纵坐标为__________. 15.【答案】11 【解析】2()366f x x x '=-+,函数()f x '的对称轴为1x =,(1)6f =,所以函数()f x 关于点(1,6)对称,因为函数()f x 在点P 处的切线与在点Q 处的切线平行,所以点P 和点Q 关于点(1,6)对称,即12p Q y y +=,而1P y =,11Q y ∴=.16.已知椭圆22:1126x y C +=,直线l 与C 在第二象限交于A ,B 两点(A 在B 的左下方),与x 轴,y 轴分别交于点M ,N ,且::1:2:3MA AB BN =,则l 的方程为____________________. 16.【答案】40x y -+=【解析】如图,由条件得B 点为线段MN 中点,设B 点坐标为00(,)x y ,得0(2,0)M x 、0(0,2)N y ,由:1:2MA AB =得A 坐标为005,33x y A ⎛⎫ ⎪⎝⎭,将A B 、坐标分别代入221126x y +=中,得220022001,126251,12969x y x y ⎧+=⎪⎪⎨⎪+=⎪⨯⨯⎩解得0022x y =-⎧⎨=⎩,则M 、N 坐标分别为()4,0-、(0,4), 故直线方程为144x y+=-,即40x y -+=,所以直线l 的方程为40x y -+=. 解法二:设(,0)M m ,(0,)N n ,则0m <,0n >,由::1:2:3MA AB BN =,可知5,66m n A ⎛⎫ ⎪⎝⎭,,22m n B ⎛⎫ ⎪⎝⎭,则AB 中点2,33m n P ⎛⎫ ⎪⎝⎭,由22MN OP b k k a ⋅=-,得221222n n n m m m -⋅=-=-,22m n ∴=,m n =-,1MNk ∴=,此时5,66m m A ⎛⎫- ⎪⎝⎭,将点A 坐标代入椭圆方程,解得:4m =-, 故102,33A ⎛⎫- ⎪⎝⎭,所以直线l 的方程为21033y x -=+,即40x y -+=.四、解答题:本大题共6小题,共70分.解答应写出文字说明、证明过程或演算步骤.17.记ABC △的内角A ,B ,C 的对边分别为a ,b ,c .已知2222b a c -=.(1)求tan tan BA的值: (2)求C 的最大值.17.【答案】(1)tan 3tan B A =-;(2)π6. 【解析】(1)由余弦定理可得2222cos b c a ac B =+-,代入2222b a c -=,得到2222(2cos )2c a ac B a c +--=,················································1分 化简得22cos 0c ac B +=,即2cos 0c a B +=.·······························································2分 由正弦定理可得sin 2sin cos 0C A B +=,即sin()2sin cos 0A B A B ++=,····························3分 展开得sin cos cos sin 2sin cos 0A B A B A B ++=,即3sin cos cos sin A B A B =-,······················4分所以tan 3tan BA=-.······································································································5分 (2)由2222b a c -=得2222b a c =-,故222cos 2a b c C ab+-=···········································6分 222222b a a b ab-+-=···································································································7分2233444a b a b ab b a +==+=≥·········································································8分 当且仅当223b a =,即b =时等号成立.··································································9分因为(0,π)C ∈,所以π6C ≤,所以C 的最大值为π6.·····················································10分18.如图,在四棱锥P ABCD -中,底面ABCD 是梯形,//AB CD ,AD CD ⊥,24CD AB ==,PAD △ 是正三角形,E 是棱PC 的中点. (1)证明://BE 平面PAD ;(2)若AD =,平面PAD ⊥平面ABCD ,求直线AB 与平面PBC 所成角的正弦值.18.【答案】(1)证明见解析;(2. 【解析】(1)取PD 中点F ,连接AF ,EF .//EF CD ,12EF CD =,//AB CD ,12AB CD =, //EF AB ∴,EF AB =,··························································································1分∴四边形ABEF 为平行四边形,//BE AF ∴,·······························································3分 又BE ⊄ 平面PAD ,AF ⊂平面PAD ,//BE ∴平面PAD .········································4分(2)取AD 中点O ,BC 中点G ,连接PO ,OG ,可得PO AD ⊥,//OG CD .平面PAD ⊥平面ABCD ,平面PAD 平面ABCD AD =,PO AD ⊥,PO ⊂平面PAD , PO ∴⊥平面ABCD .·······························································································5分 AD CD ⊥ ,//OG CD ,OG OA ∴⊥.····································································6分 以O 为原点,以AD ,OG ,OP 所在直线为x 轴、y 轴、z 轴,建立如图所示空间直角坐标系.7分 因为2AB =,4CD =,AD =,PAD △是等边三角形,所以PD AD ==12OA AD ==,3PO ==,所以A,2,0)B,(4,0)C ,(0,0,3)P . 则(0,2,0)AB =,(2,0)BC =-,(2,3)BP =-.·············································9分设平面PBC 的法向量为(,,)n x y z = ,由0BC n ⋅= ,0BP n ⋅=,可得20230y y z ⎧-+=⎪⎨-+=⎪⎩,令1x =,可得y =z =,从而n =是平面PBC 的一个法向量.······························································10分则cos ,AB n AB n AB n ⋅〈〉===⋅····································································11分所以直线AB 与平面PBC.·························································12分 19.欧拉函数*()()n n ϕ∈N 的函数值等于所有不超过正整数n ,且与n 互质的正整数的个数,例如:(1)1ϕ=,(4)1ϕ=.(1)求2(3)ϕ,3(3)ϕ;(2)令1(3)2n n a ϕ=,求数列3log n n a a ⎧⎫⎨⎬⎩⎭的前n 项和. 19.【答案】(1)2(3)6ϕ=;3(3)18ϕ=;(2)1321443n n -+-⨯. 【解析】(1)不超过9,且与其互质的数即为[1,9]中排除掉3,6,9剩下的正整数,则22(3)336ϕ=-=;································································································2分 不超过27,且与其互质的数即为[1,27]中排除掉3,6,9,12,15,18,21,24,27剩下的正整数, 则33(3)3918ϕ=-=.······························································································4分 (2)*[32,3]()k k k -∈N 表示任意相邻的三个正整数,其中与3n 互质的为32k -与31k -两个, 故分别取11,2,,3n k -= 可得[1,3]n 中与3n 互质的正整数个数为123n -⨯, 所以1(3)23n n ϕ-=⨯,11(3)32n n n a ϕ-==,···································································7分 所以31log 13n n n a n a --=.·································································································8分 设数列3log n n a a ⎧⎫⎨⎬⎩⎭的前n 项和为n T .1221122103333n n n n n T ----=+++++ ,23111221033333n n n n n T ---∴=+++++ ,···················9分两式相减得:11211111111113331133333313n n n n n n n T ---⨯--⎛⎫-=+++-=- ⎪⎝⎭- ····························10分 11111212233223n n nn n --+=--=-⨯⨯,··············································································11分 则131213212223443n n n n n T -++⎛⎫=-=- ⎪⨯⨯⎝⎭.··········································································12分 20.脂肪含量(单位:%)指的是脂肪重量占人体总重量的比例.某运动生理学家在对某项健身活动参与人群的脂肪含量调查中,采用样本量比例分配的分层随机抽样,如果不知道样本数据,只知道抽取了男性120位,其平均数和方差分别为14和6,抽取了女性90位,其平均数和方差分别为21和17.(1)试由这些数据计算出总样本的均值与方差,并对该项健身活动的全体参与者的脂肪含量的均值与方差作出估计.(结果保留整数) (2)假设全体参与者的脂肪含量为随机变量X ,且2(17,)X N σ~,其中2σ近似为(1)中计算的总样本方差.现从全体参与者中随机抽取3位,求3位参与者的脂肪含量均小于12.2%的概率. 附:若随机变量X 服从正态分布2(,)N μσ,则()0.6827P X μσμσ-+≈≤≤,(22)0.9545P X μσμσ-+≈≤≤4.7≈4.8≈,30.158650.004≈.20.【答案】(1)总样本的均值为17,方差为23;据此估计该项健身活动全体参与者的脂肪含量的总体均值为17,方差为23;(2)0.004【解析】(1)把男性样本记为12120,,,x x x ,其平均数记为x ,方差记为2x s ;把女性样本记为1290,,,y y y ,其平均数记为y ,方差记为2y s .则14x =,26x s =;21y =,217y s =.记总样本数据的平均数为z ,方差为2s .由14x =,21y =,根据按比例分配的分层随机抽样总样本平均数与各层样本平均数的关系, 可得总样本平均数为120901209012090z x y =+++·····························································2分12014902117210⨯+⨯==,··························································································3分根据方差的定义,总样本方差为1209022211121()(0i i i i s x z y z ==⎡⎤=-+-⎢⎥⎣⎦∑∑·································4分 1209022111(()210i i i i x x x z y x y z ==⎡⎤=-+-+-+-⎢⎥⎣⎦∑∑ 由1201201112)0(0iii i x x x x ==-=-=∑∑可得120120112()2()(0iii i x x x z x z x x ==--=--=∑∑同理,9090112(2((0iii i y y y z y z y y ==--=--=∑∑,·····················································5分因此,1201209090222221111()(1)(()210i i i i i i s x x x z y y y z ====⎡⎤=-+-+-+-⎢⎥⎣⎦∑∑∑∑ {}22221120(90(210x y s x z s y z ⎡⎤⎡⎤=+-++-⎣⎦⎣⎦·····························································6分 所以{}2221120[6(1417)]90[17(2117)]23210s =⨯+-+⨯+-≈, 所以总样本的均值为17,方差为23,并据此估计该项健身活动全体参与者的脂肪含量的总体均值为17,方差为23.······················7分 (2)由(1)知223 =,所以(17,23)X N ~4.8≈,所以(12.221.8)(17 4.817 4.8)0.6827P X P X =-+≈≤≤≤≤,··································8分1(12.2)(10.6827)0.158652P X <≈⨯-=,··································································9分因此(3,0.15865)X B ~,····························································································10分所以333(3)C 0.158650.004P X ==⨯≈.······································································11分 所以3位参与者的脂肪含量均小于12.2%的概率为0.004.················································12分 21.已知抛物线2:2(0)E y px p =>,过点(2,0)-的两条直线1l ,2l 分别交E 于A 、B 两点和C 、D 两点.当1l 的斜率为23时,AB =. (1)求E 的标准方程:(2)设G 为直线AD 与BC 的交点,证明:点G 必在定直线上. 21.【答案】(1)24y x =;(2)证明见解析,定直线为2x =. 【解析】(1)当1l 的斜率为23时,得1l 方程为2(2)3y x =+,·············································1分 由222(2)3y pxy x ⎧=⎪⎨=+⎪⎩,消元得2340y py p -+=,2(3)440p p ∆=--⨯>,123y y p +=,124y y p =;······························································································································2分由弦长公式得AB ===,········3分2=,解得2p =或29p =-(舍去),2p =满足0∆>,从而E 的标准方程为24y x =.····················································································4分 (2)法一:因为直线1l ,2l 分别交E 于A 、B 两点和C ,D 两点,所以直线斜率存在.设直线AB 的方程为1()2y k x =+,设211,4y A y ⎛⎫ ⎪⎝⎭,222,4y B y ⎛⎫⎪⎝⎭,由12(2)4y k x y x=+⎧⎨=⎩,消去x 得211480k y y k -+=,···························································5分 则128y y =.············································································································6分设直线CD 的方程为2()2y k x =+,233,4y C y ⎛⎫⎪⎝⎭,244,4y D y ⎛⎫⎪⎝⎭, 同理22(2)4y k x y x=+⎧⎨=⎩,消去x 得222480k y y k -+=,可得348y y =.··································7分直线AD 方程为241112241444y y y y y x y y ⎛⎫--=- ⎪⎝⎭-,即1441414y y y x y y y y =+++, 化简得14144()0x y y y y y -++=,···············································································8分 同理,直线BC 方程为23234()0x y y y y y -++=,·························································9分 因为(2,0)-在抛物线的对称轴上,由抛物线的对称性可知,交点G 必在垂直于x 轴的直线上,所以只需证G 的横坐标为定值即可. 由141423234()04()0x y y y y y x y y y y y -++=⎧⎨-++=⎩,消去y , 因为直线AD 与BC 相交,所以2314y y y y +≠+,解得2314142323144[()(())]()y y y y y y y y x y y y y +-+=+-+···········································································10分 1232341241343241231423142314231488888[()()]4[()()2]4[()()]4[()()]y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y +--+--+-+===+-++-++-+=.11分所以点G 的横坐标为2,即直线AD 与BC 的交点G 在定直线2x =上.······························12分法二:设直线AB 方程为2x my =-,由224x my y x=-⎧⎨=⎩,消去x 得2480y my -+=,··············5分设211,4y A y ⎛⎫ ⎪⎝⎭,222,4y B y ⎛⎫⎪⎝⎭,则128y y =.···································································6分 设直线CD 的方程为2x ny =-,233,4y C y ⎛⎫⎪⎝⎭,244,4y D y ⎛⎫⎪⎝⎭,同理可得348y y =.················7分 直线AD 方程为241112241444y y y y y x y y ⎛⎫--=- ⎪⎝⎭-,即1441414y y y x y y y y =+++, 化简得14144()0x y y y y y -++=,···············································································8分 同理,直线BC 方程为23234()0x y y y y y -++=.·························································9分 因为(2,0)-在抛物线的对称轴上,由抛物线的对称性可知,交点G 必在垂直于x 轴的直线上,所以只需证G 的横坐标为定值即可. 由141423234()04()0x y y y y y x y y y y y -++=⎧⎨-++=⎩,消去y ,因为直线AD 与BC 相交,所以2314y y y y +≠+, 解得2314142323144[()(())]()y y y y y y y y x y y y y +-+=+-+···········································································10分1232341241343241231423142314231488888[()()]4[()()2]4[()()]4[()()]y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y +--+--+-+===+-++-++-+=.11分。
福州市高中毕业班文科数学质量检查2021年福州市高中毕业班质量反省数学〔文科〕试卷参考答案及评分规范一、选择题〔本大题共12小题,每题5分.〕 1.A 2.B 3.D 4.B 5.D 6.C 7.C8.B9.A10.C11.A12.D二、填空题〔本大题共4小题,每题4分,共16分.〕 13.i14.1415.116.1()3n三、解答题〔本大题共6小题,共74分.〕 17.解:〔Ⅰ〕由得112n n a a +=+,即112n n a a +-=. ········································ 1分 ∴ 数列{}n a 是以12为首项,以12d =为公差的等差数列. ································· 2分 ∵ 1(1),n a a n d =+- ················································································· 3分 ∴ 11(1)222n na n =+-=〔*n N ∈〕. ·························································· 6分 〔Ⅱ〕由〔Ⅰ〕得141(1)22nb n n n n ==++⋅, ················································· 7分 ∴ 114()1n b n n =-+. ············································································ 9分 ∴ 111114[(1)()()]2231n T n n =-+-++-+14(1)1n =-+41n n =+. ···················· 12分 18.解:〔Ⅰ〕事情A 包括的基身手情为:{,}a b 、{,}a c 、{,}a x 、{,}a y 、{,}b c 、{,}b x 、{,}b y 、{,}c x 、{,}c y ,{,}x y ,共10个. ······································································ 6分 注:⑴ 漏写1个情形扣2分,扣完6分为止;多写情形一概扣3分. 〔Ⅱ〕方法一:记 〝至少有1扇门被班长关闭〞为事情B .∵ 事情B 包括的基身手情有{,}a x 、{,}a y 、{,}b x 、{,}b y 、{,}c x 、{,}c y ,{,}x y ,共7个. ···················································································································· 9分∴ 7()10P B =. ······················································································ 12分 方法二:事情〝2个门都没被班长关闭〞 包括的基身手情有{,}a b 、{,}a c 、{,}b c ,共3个. ·································································· 8分∴ 2个门都没被班长关闭的概率1310P =, ···················································· 10分 ∴ 至少有1个门被班长关闭的概率23711010P =-=.······································ 12分 19.方法一:由sin()04x π-≠,得4x k ππ-≠〔k ∈Z 〕,即4x k ππ≠+〔k ∈Z 〕,∴ 函数()f x 定义域为{|,}4x x k k ππ≠+∈Z . ··············································· 2分 ∵cos 2(),sin()4x f x x π=-22cos sin ()cos sin )cos sin 4x x f x x x x x x π-∴==+=+-, ······································ 5分 注:以上的5分全部在第Ⅱ小题计分.〔Ⅰ〕()sin()121243f ππππ=+===································ 8分 〔Ⅱ〕令322(242Z)k x k k πππππ+<+<+∈, ·········································· 10分 得522(44Z),k x k k ππππ+<<+∈ ··························································· 11分 ∴ 函数()f x 的单调递减区间为5(2,2)44k k ππππ++(Z)k ∈. ····················· 12分 注:先生假定未求函数的定义域且将单调递减区间求成闭区间,只扣2分. 方法二:由sin()04x π-≠,得4x k ππ-≠〔k ∈Z 〕,即4x k ππ≠+〔k ∈Z 〕,∴ 函数()f x 定义域为{|,}4x x k k ππ≠+∈Z . ············································· 2分 ∵cos 2(),sin()4x f x x π=-sin 2()2sin()cos()444())4sin()sin()44x x x f x x x x ππππππ---∴==---, ························ 5分〔Ⅰ〕()cos())121246f ππππ=--= ··························· 8分〔Ⅱ〕令22()4k x k k Z ππππ<-<+∈, ·················································· 10分 得522(44Z)k x k k ππππ+<<+∈, ························································· 11分 ∴ 函数()f x 的单调递减区间为5(2,2)44k k ππππ++(Z)k ∈. ····················· 12分 方法三:〔Ⅰ〕∵cos(2)cos126ππ⨯==,1sin()sin 41262πππ-==, ∴2()1122f π=. ········································································ 3分 下同方法一、二.20.解:〔Ⅰ〕依题意,点P 坐标为(,0)a . ················································ 1分 ∵ 6OP OQ ⋅=,点Q 坐标为(3,3),∴ 3306a +⨯=,解得2a =. ··································································· 3分∴ 椭圆C 的方程为22149x y +=. ································································ 4分 〔Ⅱ〕过点Q (3,3)且斜率为32的直线AB 方程为33(3)2y x -=-,即3230x y --=. ···················································································· 5分 方法一:设点A 、B 的坐标区分为11(,)x y 、22(,)x y ,由221,493230,x y x y ⎧+=⎪⎨⎪--=⎩消去x 并整理得,2812270y y +-=. ·································· 6分 ∴ 1212327,28y y y y +=-=-, ··································································· 7分 ∴ 2212121295463()()4444y y y y y y -=+-=+=, ∴12||y y -=. ················································································ 9分 ∵ 直线AB 与x 轴的交点为(1,0)M , ∴AOB ∆的面积AOB OMA OMBS S S ∆∆∆=+121211||(||||)1||22OM y y y y =⋅+=⨯⨯-. ·············· 12分 方法二:设点A 、B 的坐标区分为11(,)x y 、22(,)x y ,由221,493230,x y x y ⎧+=⎪⎨⎪--=⎩消去y 并整理得22230x x --=, ············ 6分 ∴12,x x ==, ········································· 7分 ∴12|||AB x x =-= ·· 9分 ∵ 点O 到直线AB的距离d ===, ····································· 10分 ∴AOB ∆的面积1122AOB S AB d ∆=⋅⋅==. ·························· 12分 方法三:设点A 、B 的坐标区分为11(,)x y 、22(,)x y ,由221,493230,x y x y ⎧+=⎪⎨⎪--=⎩消去y 并整理得22230x x --=, ············ 6分 ∴12,x x ==, ········································· 8分 ∵ 直线AB 与y 轴的交点为3(0,)2M -,∴AOB ∆的面积AOB OMA OMB S S S ∆∆∆=+12113||(||||)222OM x x =⋅+=⨯⨯=12分 方法四:设点A 、B 的坐标区分为11(,)x y 、22(,)x y ,由221,493230,x y x y ⎧+=⎪⎨⎪--=⎩消去y 并整理得22230x x --=, ········································ 6分 ∴ 121231,2x x x x +=⋅=-, ······································································· 7分∴12||AB x x -==·············································································································· 9分∵ 点O 到直线AB的距离d ===, ··································· 10分 ∴AOB ∆的面积1122AOB S AB d ∆=⋅⋅==. ·························· 12分 21.〔Ⅰ〕证明:在菱形ABCD 中,∵ BD AC ⊥,∴ BD AO ⊥. ························································································· 1分 ∵ EF AC ⊥,∴PO EF ⊥,∵ 平面PEF ⊥平面ABFED ,平面PEF平面ABFED EF =,且PO ⊂平面PEF ,∴ PO ⊥平面ABFED , ·········································································· 2分 ∵ BD ⊂平面ABFED ,∴ PO BD ⊥. ························································································· 3分 ∵ AOPO O =,所以BD ⊥平面POA .······················································ 4分 〔Ⅱ〕连结OB ,设AO BD H =.由〔Ⅰ〕知,AC BD ⊥. ∵ 60DAB ∠=︒,4BC =,∴ 2BH =,CH = ········································································· 5分 设OH x =〔0x <<由〔Ⅰ〕知,PO ⊥平面ABFED ,故POB ∆为直角三角形. ∴ 222222()PB OB PO BH OH PO =+=++,∴222224)2162(10PB x x x x =++=-+=+. ······················ 7分事先x =PB 取得最小值,此时O 为CH 中点. ········································· 8分 ∴ 14CEF BCD S S ∆∆=, ················································································· 9分 ∴ 3344BCD ABD BFED S S S ∆∆==梯形, ································································ 10分 ∴ 1211,33ABD BFED V S PO V S PO ∆=⋅=⋅梯形. ················································· 11分 ∴1243ABD BFED V S V S ∆==梯形.∴ 当PB 取得最小值时,12:V V 的值为4:3. ················································ 12分22.解:〔Ⅰ〕22(1)(1)()2x x f x x x x+-'=-+=-〔0x >〕, ····························· 1分 由()0,0f x x '>⎧⎨>⎩得,01x <<;由()0,0f x x '<⎧⎨>⎩得,1x >. ∴ ()f x 在(0,1)上为增函数,在(1,)+∞上为减函数. ······································· 3分 ∴ 函数()f x 的最大值为(1)1f =-. ···························································· 4分 〔Ⅱ〕∵ ()a g x x x =+, ∴ 2()1a g x x'=-. 〔ⅰ〕由〔Ⅰ〕知,1x =是函数()f x 的极值点, 又∵ 函数()f x 与()a g x x x =+有相反极值点, ∴ 1x =是函数()g x 的极值点,∴ (1)10g a '=-=,解得1a =. ································································· 7分 经检验,事先1a =,函数()g x 取到极小值,契合题意. ···································· 8分 〔ⅱ〕∵ 211()2f e e =--,(1)1f =-,(3)92ln3f =-+, ∵ 2192ln321e -+<--<-, 即 1(3)()(1)f f f e<<, ∴ 11[,3]x e ∀∈,1min 1max ()(3)92ln3,()(1)1f x f f x f ==-+==-. ···················· 9分 由〔ⅰ〕知1()g x x x =+,∴21()1g x x '=-. 事先1[,1)x e ∈,()0g x '<;事先(1,3]x ∈,()0g x '>.故()g x 在1[,1)e 为减函数,在(1,3]上为增函数.∵ 11110(),(1)2,(3)333g e g g e e =+==+=, 而 11023e e <+<, 1(1)()(3),g g g e ∴<<∴ 21[,]x e e ∀∈,2min 2max 10()(1)2,()(3)3g x g g x g ====. ······························ 10分 ① 当10k ->,即1k >时, 关于121,[,]x x e e ∀∈,不等式12()()11f xg x k -≤-恒成立12max 1[()()]k f x g x ⇔-≥-12max [()()]1k f x g x ⇔≥-+12()()(1)(1)123f x g x f g -≤-=--=-,∴ 312k ≥-+=-,又∵ 1k >,∴ 1k >. ····························································································· 12分 ② 当10k -<,即1k <时, 关于121,[,]x x e e ∀∈,不等式12()()11f x g x k -≤-12min 1[()()]k f x g x ⇔-≤-12min [()()]1k f x g x ⇔≤-+.∵ 121037()()(3)(3)92ln32ln333f x g x f g -≥-=-+-=-+, ∴ 342ln33k ≤-+. 又∵1k <,∴ 342ln33k ≤-+. 综上,所求的实数k 的取值范围为34(,2ln3](1,)3-∞-++∞. ··························· 14分。
2023~2024学年福州市高三年级第一次质量检测数学试题(完卷时间120分钟;满分150分)第Ⅰ卷一、选择题:本题共8小题,每小题5分,共40分.在每小题给出的四个选项中,只有一项是符合题目要求的.1.已知复数z 满足11i z=−,则在复平面内,z 对应的点在( )A .第一象限B .第二象限C .第三象限D .第四象限2.已知集合{}21A x x=<,{}0B x x =>,则A B = ( )A .(0,1)B .()0,+∞C .()1,−+∞D .(),−∞+∞3.已知点()0,2P x 在抛物线C :24y x =上,则P 到C 的准线的距离为( ) A .4B .3C .2D .14.“二十四节气”是中国古代劳动人民伟大的智慧结晶,其划分如图所示.小明打算在网上搜集一些与二十四节气有关的古诗.他准备在春季的6个节气与夏季的6个节气中共选出3个节气,若春季的节气和夏季的节气各至少选出1个,则小明选取节气的不同情况的种数是( )A .90B .180C .270D .3605.一个正四棱台形油槽可以装煤油3190000cm ,其上、下底面边长分别为60cm 和40cm ,则该油槽的深度为( ) A .75cm 4B .25cmC .50cmD .75cm6.一个袋子中有大小和质地相同的4个球,其中有2个红球,2个黄球,每次从中随机摸出1个球,摸出的球不再放回,则第二次摸到黄球的条件下,第一次摸到红球的概率为( ) A .13B .12C .23D .347.已知1ea =,ln b =,ln c =,则( ) A .a b c >> B .b c a >> C .a c b >>D .c a b >>8.若定义在R 上的函数()()sin cos 0f x x x ωωω=+>的图象在区间[]0,π上恰有5条对称轴,则ω的取值范围为( ) A .1721,44B .1725,44C .1725,44D .3341,44二、选择题:本题共4小题,每小题5分,共20分.在每小题给出的四个选项中,有多项符合题目要求,全部选对的得5分,部分选对的得2分,有选错的得0分.9.某市抽查一周空气质量指数变化情况,得到一组数据:80,76,73,82,86,75,81.以下关于这组数据判断正确的有( ) A .极差为13B .中位数为82C .平均数为79D .方差为12410.已知圆M :221x y +=,直线l :(1y k x =−,则( )A .l 恒过定点)1−B .若l 平分圆周M ,则k =C .当k =l 与圆M 相切D .当k <<时,l 与圆M 相交11.已知函数()332f x x ax =−+有两个极值点.则( ) A .()f x 的图象关于点()0,2对称 B .()f x 的极值之和为-4C .a ∃∈R ,使得()f x 有三个零点D .当01a <<时,()f x 只有一个零点12.已知正四棱柱1111ABCD A B C D −的底面边长为2,球O 与正四棱柱的上、下底面及侧棱都相切,P 为平面1CDD 上一点,且直线BP 与球O 相切,则( ) A .球O 的表面积为4π B .直线1BD 与BP 夹角等于45°C .该正四棱柱的侧面积为D .侧面11ABB A 与球面的交线长为2π第Ⅱ卷注意事项:用0.5毫米黑色签字笔在答题卡上书写作答.在试题卷上作答,答案无效. 三、填空题;本大题共4小题,每小题5分,共20分.13.已知向量()1,2a = ,()1,2b λλ=+−,若a b ⊥ ,则实数λ的值为__________.14.将圆周16等分,设每份圆弧所对的圆心角为θ,则sin cos θθ的值为__________.15.已知定义城为R 的函数()f x 同时具有下列三个性质,则()f x =__________.(写出一个满足条件的函数即可) ①()()()f x y f x f y +=+;②()f x ′是偶函数;③当0x y +>时,()()0f x f y +<.16.已知双曲线C :()222210,0x y a b a b−=>>的左焦点为F ,两条渐近线分别为1l ,2l .点A 在1l 上,点B在2l 上,且点A 位于第一象限,原点O 与B 关于直线AF 对称、若2AF b =,则C 的离心率为__________.四、解答题:本大题共6小题,共70分.解答应写出文字说明、证明过程或演算步骤.17.(本小题满分10分)已知等比数列{}n a 的前n 项和为n S ,且12n n a S +=+. (1)求{}n a 的通项公式;(2)若221log n n b a −=,求数列{}n b 的前n 项和n T . 18.(本小题满分12分)记ABC △的内角A ,B ,C 所对的边分别为a ,b ,c ,已知b =,6B π=.(1)若2c =,求a ;(2)求ABC △面积的最大值. 19.(本小题满分12分)国际上常采用身体质量指数(Body Mass Index ,缩写BMI )来衡量人体肥瘦程度,其计算公式是()()22kg BMI m=体重单位:身高单位:.为了解某公司员工的身体肥瘦情况,研究人员从该公司员工体检数据中,采用比例分配的分层随机抽样方法抽取了50名男员工、30名女员工的身高和体重数据.计算得到他们的BMI(1)若该公司男员工有1500名,则该公司共有多少名员工?(2)以频率估计概率,分别从该公司男、女员工中各随机抽取2名员工,求抽到的员工中至少有一名是肥胖的概率.20.(本小题满分12分)如图,在底面为菱形的四棱锥M ABCD −中,2AD BD MB ===,MA MD ==(1)求证:平面MAD ⊥平面ABCD ;(2)已知2MN NB =,求直线BN 与平面ACN 所成角的正弦值.21.(本小题满分12分)已知椭圆E :22143x y +=的右焦点为F ,左、右顶点分别为A ,B .点C 在E 上,()4,P P y ,()4,Q Q y 分别为直线AC ,BC 上的点. (1)求P Q y y ⋅的值;(2)设直线BP 与E 的另一个交点为D ,求证:直线CD 经过F .22.(本小题满分12分)已知函数()ln f x x a =−,记曲线()y f x =在点()()11,x f x 处的切线为l ,l 在x 轴上的截距为()220x x >.(1)当1e x =,1a =时,求切线方程; (2)证明:12e e a a x x −≥−.答案一、单项选择题:本题共8小题,每小题5分,共40分.在每小题给出的四个选项中,只有一项是符合题目要求的.1.【考查意图】本小题以复数为载体,主要考查复数的基本运算、几何意义等基础知识;考查运算求解能力、推理论证能力;考查数学运算、逻辑推理等数学核心素养,体现基础性. 【答案】A .【解析】由11i z =−得11i1i 2z+==−,应选A . 2.【考查意图】本小题以不等式为载体,主要考查集合运算等基础知识;考查运算求解能力、推理论证能力;考查数学运算、逻辑推理等核心素养,体现基础性. 【答案】C . 【解析】{}11A x x =−<<,{}0B x x =>,故()1,A B =−+∞ ,应选C . 3.【考查意图】本小题以抛物线为载体,主要考查抛物线的图象和性质、直线与抛物线的位置关系等基础知识;考查运算求解能力、推理论证能力;考查数形结合思想、化归与转化思想;考查直观想象、逻辑推理、数学运算等核心素养,体现基础性. 【答案】C .【解析】抛物线24y x =的准线为1x =−,由P C ∈得01x =,故P 到准线的距离为2,应选C .4.【考查意图】本小题以二十四节气为载体,主要考查排列与组合等基础知识;考查运算求解能力、推理论证能力和应用意识;考查数学运算、逻辑推理等核心素养,体现基础性和应用性. 【答案】B .【解析】根据题意可知,小明可以选取1春2夏或2春1夏.其中1春2夏的不同情况有:1266C C 90⋅=种;2春1夏的不同情况有:2166C C 90⋅=种,所以小明选取节气的不同情况有:9090180+=种.应选B .5.【考查意图】本小题以正四棱台形油槽为载体,主要考查空间几何体的体积等基础知识;考查空间想象能力、推理论证能力、运算求解能力;考查数形结合思想、化归与转化思想;考查直观想象、逻辑推理、数学运算等核心素养,体现基础性和应用性. 【答案】D .【解析】设正四棱台的高,即深度为cm h ,依题意,得()22190000604060403h=++×,解得75h =,应选D .6.【考查意图】本小题主要考查条件概率、全概率公式等基础知识;考查推理论证能力、运算求解能力与创新意识;考查化归与转化思想;考查数学建模、逻辑推理、数据分析等核心素养,体现综合性、应用性与创新性. 【答案】C .【解析】解法一:记第i 次摸到红球为事件i A ,摸到黄球为事件()1,2i B i =,则()()()()()21211211211123232P B P A P B A P B P B B =+=×+×=,()()()12121221433P A B P A P B A ==×=,故()()()1212223P A B P A B P B ==.应选C . 解法二:记第i 次摸到红球为事件i A ,摸到黄球为事件()1,2i B i =.由抽签的公平性可知()22142P B ==,又()12221433P A B ×==×,所以()()()1212223P A B P A B P B ==.应选C . 7.【考查意图】本小题以数的大小比较为载体,主要考查函数与导数等基础知识;考查运算求解能力、推理论证能力、应用意识;考查数学建模、数学运算、逻辑推理等核心素养,体现基础性、应用性和综合性. 【答案】A . 【解答】解法一:1ln e e e a ==,ln 2ln 4ln 24b ==,ln 55c ,令()ln x f x x =,()21ln xf x x−′=,当e x ≥时,()0f x ′≤,故()f x 在区间[)e,+∞上单调递减,所以a b c >>.==>,所以ln ln >b c >.在同一坐标系中作出函数()2xf x =,()2g x x =的图象,如图所示,由图可知,()()e e f g <,即e22e <,所以e22e 2e 2e <,即11e22e <,所以111ln 2ln e 2e e<=,即b a <. (令()ln x f x x=,()21ln xf x x −′=,当0e x <<时,()0f x ′>,故()f x 在区间()0,e 上单调递增,所以1ln e ln 2e e 2a b ==>=.) 综上,a b c >>.应选A .8.【考查意图】本小题以三角函数为载体,考查三角函数的图象与性质、三角恒等变换等基础知识;考查抽象概括能力、推理论证能力、应用意识;考查数形结合思想;考查直观想象、逻辑推理、数学运算等核心素养,体现基础性和综合性. 【答案】A .【解析】由已知,()4f x x πω=+,令42x k ππωπ+=+,k ∈Z ,得()414k x πω+=,k ∈Z ,依题意知,有5个整数k 满足()4104k ππω+≤≤,即0414k ω≤+≤,所以0,1,2,3,4k =,则4414451ω×+≤<×+,故172144ω≤<,应选A . 二、多项选择题:本题共4小题,每小题5分,共20分.在每小题给出的四个选项中,有多项符合题目要求.全部选对的得5分,部分选对的得2分,有选错的得0分.9.【考查意图】本小题主要考查极差、中位数、平均数、方差等基础知识;考查推理论证能力、运算求解能力;考查化归与转化思想;考查数据分析等核心素养,体现基础性. 【答案】AC .10.【考查意图】本小题以直线与圆为载体,考查直线的方程、圆的方程、直线与圆的位置关系等基础知识;考查运算求解能力;考查直观想象、逻辑推理等核心素养;体现基础性和综合性. 【答案】BC .【解析】依题意,l恒过定点()1−,选项A 错误;若l 平分圆周M ,则l 经过圆M 的圆心()0,0,代入直线方程得k =B 正确; 圆心()0,0O 到l的距离dk =1d r ==,l 与圆M 相切,选项C 正确;若l 与圆M相交,则1d <,即)2211k −<+,即0k <<,故选项D 错误.综上,应选BC .11.【考查意图】本小题以三次函数为载体,主要考查函数与导数等基础知识;考查运算求解能力、推理论证能力、应用意识;考查数学建模、数学运算、逻辑推理等核心素养,体现基础性、应用性和综合性. 【答案】ACD .【解答】()f x 的图象可由奇函数()33g x x ax =−的图象向上平移2个单位长度得到,故()f x 的图象关于点()0,2对称,选项A 正确.设()f x 的极值点分别为()1212,x x x x <,则由对称性可知120x x +=,故()()12224f x f x +=×=,即()f x 的极值之和为4,选项B 错误.依题意,方程()2330f x x a ′=−=有两异根,则0a >,1x =2x =,()f x在区间(−∞上单调递增,在区间(上单调递减,在区间)+∞单调递增.由图象可知,当()()120f x f x >>时,()f x 的图象与x 轴有3个交点,即()f x 有3个零点,选项C 正确.当01a <<时,(32210f=−+=−>,此时()f x 只有一个零点,选项D 正确.综上,应选ACD .12.【考查意图】本小题以正四棱柱为载体,主要考查球、直线与平面的位置关系等基础知识;考查空间想象能力、推理论证能力、运算求解能力;考查化归与转化思想;考查直观想象、逻辑推理等核心素养,体现基础性、应用性和综合性. 【答案】BCD .【解答】如图,设球O 与下底面相切于点1O ,则1OO ⊥平面ABCD ,连接1O A ,则1OAO ∠为直线OA 与平面ABCD 所成的角.因为球O与正四棱柱的侧棱相切,所以其半径11R OO O A===,所以428S ππ=⋅=表,四棱柱的侧面积为()24××,故选项A 错误,C 正确.依题意,1BB ,BP 均为球O 的切线,1BD 经过球心O ,所以111B BD PBD ∠=∠,又111B D BB =,所以11145PBD B BD ∠=∠=°,选项B 正确.对于选项D ,棱1AA 的中点F ,即球O 与棱1AA 的切点应为交线上的点,故交线应为过F 的圆.截面圆的圆心即为矩形11ABB A 的中心E ,在Rt OEF △中,OFR ==,112OEBC ==,所以截面圆半径1r EF ==,周长为2π,该选项正确.综上,应选BCD .三、填空题:本大题共4小题,每小题5分,共20分.13.【考查意图】本小题以平面向量为载体,主要考查平面向量的基本运算等基础知识;考查运算求解能力、推理论证能力;考查数学运算、逻辑推理、直观想象等核心素养,体现基础性. 【答案】5.【解析】由a b ⊥得()()1220λλ++−=,解得5λ=. 14.【考查意图】本小题以圆的等分为载体,考查三角恒等变换等基础知识;考查推理论证能力,抽象概括能力;考查逻辑推理等核心素养;体现基础性与应用性..【解析】依题意,得8πθ=,所以11sin cos sin 2sin 224πθθθ===. 15.【考查意图】本小题以函数的性质为载体,考查函数的奇偶性、函数与导数等基础知识;考查推理论证能力;考查逻辑推理等核心素养;体现基础性、综合性与应用性. 【答案】x −(答案不唯一,()0kx k <均可).16.【考查意图】本小题以双曲线为载体,主要考查双曲线的离心率、双曲线的图象和性质、直线与双曲线的位置关系等基础知识;考查运算求解能力、推理论证能力;考查数形结合思想、化归与转化思想;考查直观想象、逻辑推理、数学运算等核心素养,体现基础性和综合性. 【答案】2.【解答】依题意,1l 的方程为by x a=,2AF l ⊥,设垂足为P ,则FP b =.因为22AFb FP ==,所以点F ,A 关于直线2l 对称,FOP AOP ∠=∠,又1l ,2l 关于y 轴对称,所以1l 的倾斜角为1180603×°=°,故tan 60ba=°=,所以离心率2e =.四、解答题:本大题共6小题,共70分.解答应写出文字说明、证明过程或演算步骤.17.【命题意图】本小题主要考查等差数列、等比数列、递推数列及数列求和等基础知识,考查运算求解能力、逻辑推理能力和创新能力等,考查化归与转化思想、分类与整合思想、函数与方程思想、特殊与一般思想等,考查逻辑推理、数学运算等核心素养,体现基础性和综合性.满分10分. 【解答】(1)解法一:由12n n a S +=+得21322,2,a S aS =+ =+设等比数列{}n a 的公比为q ,所以()()12112,12,a q a q q −=−−= 解得12,2,a q == 或12,a q =− = (舍去).所以2n n a =.(2)212212log log 221n n n b a n −−===−, 故11b =,()()12121122n n b b n n n −−=−−−−=≥ , 所以{}n b 是首项为1,公差为2的等差数列, 所以()()1212122n n n b b n n T n ++−===.解法二:(1)因为12n n a S +=+,① 所以当2n ≥时,12n n a S −=+,② ①-②得12n n a a +=, 所以等比数列{}n a 的公比12n na qa +==. 由①式得212a a =+,得12a =,所以2n n a =.(2)12n n T b b b =++⋅⋅⋅+2123221log log log n a a a −++⋅⋅⋅+()21321log n a a a −⋅⋅⋅= ()13212log 2n ++⋅⋅⋅+−=()12122log 2n n+− =2n =.18.【命题意图】本小题主要考查正弦定理、余弦定理及三角恒等变换等基础知识,考查逻辑推理能力、运算求解能力等,考查化归与转化思想、函数与方程思想、数形结合思想等,考查数学运算、逻辑推理等核心素养,体现基础性和综合性.满分12分.【解答】解法一:(1)因为b =,2c =,6B π=,根据余弦定理得2222cos b a c ac B =+−,所以22224cos6a a π=+−,即220a −+=,解得1a =.(2)根据余弦定理,得2222cos a b c ac B =+−,所以(222222cos 226a c ac a c ac ac π=+−=+−≥−=,(当且仅当1a c ==时取等号),即(22ac ≤=+,所以ABC △面积(1111sin sin 2222644ABC S ac B ac ac π===≤×△,即ABC △.解法二:(1)因为b =,2c =且6B π=,根据正弦定理,得sin sin b c B C=,2sin C=,即sin C =, 因为c b >,所以C B >,所以566C ππ<<, 所以4C π=或34C π=, 当4C π=时,()1sin sin sin 642A B C ππ =+=+= , 根据正弦定理,得sin sin a bA B=, 所以sin 1sin b Aa B ==+;当34C π=时,()31sin sin sin 642A B C ππ =+=+=×= ,根据正弦定理,得sin sin a bA B=, 所以sin 1sin b A a B ==; 综上,1a =.(2)略,同解法一.解法三:(1)因为b =,2c =且6B π=, 根据正弦定理,得sin sin b cB C=, 2sin C=,即sin C =, 因为c b >,所以C B >,所以566C ππ<<, 所以4C π=或34C π=,当4C π=时,()76412A B C πππππ =−+=−+= , 根据正弦定理,得sin sin a b A B=,所以sin sin cos cos sin sin 343434b A a B ππππππ ==+=+ ;sin cos cos sin 13434ππππ ++; 当34C π=时,()36412A B C πππππ =−+=−+= , 根据正弦定理,得sin sin a b A B =,所以sin sin cos cos sin sin 343434b A a B ππππππ ==−=−sin cos cos sin 13434ππππ −− ;综上,1a =.(2)根据正弦定理,得sin sin sin ac b A C B ===,所以a A =,c C =,即(251sin sin 8sin sin 8sin cos 62aC A C A A A A A π ==−=+21cos 22sin 22sin 22sin 222A A A A A A −=−=+=++14sin 224sin 223A A A π +−+= 因为506A π<<,所以42333A πππ−<−<, 所以当232A ππ−=,即512A π=时,sin 23A π −取得最大值为1,即ac最大值为4+,所以ABC △面积(1111sin sin 422644ABC S ac B ac ac π===≤×+△,即ABC △. 19.【命题意图】本小题主要考查分层抽样、独立事件的概率、互斥事件、对立事件的概率等基础知识;考查数学建模能力,运算求解能力,逻辑推理能力,创新能力以及阅读能力等;考查统计与概率思想、分类与整合思想等;考查数学抽象,数学建模和数学运算等核心素养;体现应用性和创新性.满分12分.【解】(1)设该公司共有x 名员工, 依题意得1500505030x =+, 解得2400x =, 所以该公司共有2400名员工.(2)依题意,事件“抽到一名男员工不为肥胖”的概率为404505=,事件“抽到一名女员工不为肥胖”的概率为2793010=, 由事件的独立性,得抽到的两个男员工都不存在肥胖的概率为44165525×=, 抽到的两个女员工都不存在肥胖的概率为99811010100×=, 设事件M 为“抽到的员工中至少有一名是肥胖”,则事件M 为“抽到的员工都不存在肥胖”, 所以()811632410025625P M =×=, 所以()3243011625625P M =−=, 所以抽到的员工中至少有一名是肥胖的概率为301625. 20.【命题意图】本小题主要考查直线与直线、直线与平面、平面与平面的位置关系,直线与平面所成角等基础知识;考查空间想象能力,逻辑推理能力,运算求解能力等;考查化归与转化思想,数形结合思想,函数与方程思想等;考查直观想象,逻辑推理,数学运算等核心素养;体现基础性和综合性.满分12分.【解答】(1)取AD 的中点为O ,连结OM ,OB ,因为四边形ABCD 是为菱形,且2AD BD ==,所以ABD △为正三角形,所以BO AD ⊥,且BO =.因为MAMD ==,所以MO AD ⊥,所以1MO =,又因为2MB =,所以222MO BO MB +=,所以MO BO ⊥,因为AD BO O ∩=,AD ⊂平面ABCD ,BO ⊂平面ABCD所以MO ⊥平面ABCD ,又因为MO ⊂平面MAD ,所以平面MAD ⊥平面ABCD .(2)由(1)知,OA ,OB ,OM 两两垂直,故以O 为坐标原点,分别以OA ,OB ,OM 为x ,y ,z 轴的正方向建立如图所示的空间直角坐标系O xyz −.则()1,0,0A,()B,()C −,()0,0,1M,13N ,所以()3,CA =,12,3CN =,()2,0,0CB = , 设平面ACN 的法向量为(),,n x y z = , 则0,0,n CA n CN ⋅= ⋅=即30,120,3x x y z = +=取1x =,则()3n − .因为()0,BM = ,则cos ,BM n BM n BM n⋅=== , 所以直线BN 与平面ACN21.【命题意图】本小题主要考查椭圆的标准方程及简单几何性质,直线与圆、椭圆的位置关系,平面向量等基础知识;考查运算求解能力,逻辑推理能力,直观想象能力和创新能力等;考查数形结合思想,函数与方程思想,化归与转化思想等;考查直观想象,逻辑推理,数学运算等核心素养;体现基础性,综合性与创新性.满分12分.【解答】(1)依题意,()2,0A −,()2,0B .设()11,C x y ,则2211143x y +=, 直线AC 方程为()1122y y x x ++,令4x =得1162P y y x =+, 直线BC 方程为()1122y yx x −−,令4x =得1122Q y y x =−, 所以2121124P Q y y y x =− 2121123144x x ×− =− 9=−,即P Q y y ⋅的值为9−.(2)设()22,D x y ,()4,P t ,则直线AP 方程为()26t y x =+,直线BP 的方程为()22t y x =−, 由()222,63412t y x x y =+ +=得()222227441080t x t x t +++−=, 所以2124108227t x t −−=+,即21254227t x t −=+,故()112182627t t y x t=+=+. 由()222,23412t y x x y =− +=得()2222344120t x t x t +−+−=, 所以22241223t x t −=+,即222263t x t −=+,故()2226223t t y x t −=−=+. 所以()()122111x y x y −−−2222222736918273327t t t t t t t t−−−=⋅−⋅++++ ()()()222262733270327t t t t t −−+−=++,又()1,0F ,所以向量()111,FC x y =− ,与()221,FD x y =− 共线,所以直线CD 经过F . 解法二:(1)依题意,()2,0A −,()2,0B .设()11,C x y ,则2211143x y +=, 所以111122AC BC y y k k x x ⋅=⋅+− 21214y x =− 21213144x x −−= 34=−. 即B 344242Q P AP Q y y k k −=⋅=⋅+−,故P Q y y 的值为9−. (2)设()11,C x y ,()22,D x y ,()4,P t .要证直线CD 经过()1,0F ,只需证向量()111,FC x y =− ,与()221,FD x y =− 共线,即证()()122111x y x y −=−.(*) 因为()2222112014343x y −+==+,所以111123246P AC y x y k x y −==−⋅=+, 同理可得222223242P BD y x y k x y +==−⋅=−, 所以()()21122123AC BD x y k k x y −==+,即1221123620x y x y y y −++=,① 同理可得1221123260x y x y y y −+++=,②①-②得12211244440x y x y y y −+−=,即()()122111x y x y −=−.所以(*)式成立,命题得证.22.【命题意图】本小题主要考查导数,函数的单调性、零点、不等式等基础知识;考查逻辑推理能力,直观想象能力,运算求解能力和创新能力等;考查函数与方程思想,化归与转化思想,分类与整合思想等;考查逻辑推理,直观想象,数学运算等核心素养;体现基础性、综合性和创新性.满分12分.【解答】(1)()1f x x′=, 当1e x =,1a =时,()1ln e 10f x =−=,即切点为()e,0, 所以所求切线斜率()1e ek f ′=, 所以所求的切线方程为()1e e y x =−,即11ey x =−. (2)由于()11ln f x x a =−, 所以切线l 的方程为()()1111ln y x a x x x −−=−. 令0y =,得()()1111ln x a x x x −−=−,解得()2111ln x x x x a =−−.(*) 由20x >,得11e a x +<. 构造函数()()ln g x x x x a =−−, 所以()ln g x a x ′=−,所以当0e a x <<时,()0g x ′>,()x 单调递增;当e a x >时,()0g x ′<,()g x 单调递减.故()()max e e a a g x g ==.所以2e a x ≤.若1e a x ≤,由(*)式知12x x ≤,所以12e a x x ≤≤, 故12e e a a x x −≥−.若1e a x >,则()()()121212e e e e 2e a a a a a x x x x x x −−−=−−−=+−, 所以()12111e e 2ln 2e a a a x x x x x a −−−=−−−.构造函数()()()12ln 2e e e aa a x x x x a x ϕ+=−−−<<,所以()()1ln 0x a x ϕ′=+−>,故()x ϕ在区间()1e ,e a a +上单调递增, 所以()()e 0a x ϕϕ>=,所以()1112ln 2e 0a x x x a −−−>,即 所以12e e 0a a x x −−−>,即12e e a a x x −>−. 综上,不等式成立12e e a a x x −≥−成立(当且仅当1e a x =时取等号).。
2024-2025学年福州市高三年级第一次质量检测数学答案一、单项选择题:本题共8小题,每小题5分,共40分.在每小题给出的四个选项中,只有一项是符合题目要求的。
有多项符合题目要求。
全部选对的得6分,部分选对的得部分分,有选错的得0分。
15. (13分)已知数列{}n a 满足12a =,132n n a a +=+. (1)证明:数列{}1n a +是等比数列; (2)求{}n a 的前n 项和n S .【解法一】(1)证明:因为132n n a a +=+,且12a =,所以10n a +≠, ··················································································· 1分 所以1132111n n n n a a a a ++++=++ ········································································ 3分 3(1)31n n a a +==+, ···································································· 5分 又113a +=,所以数列{}1n a +是以3为首项,3为公比的等比数列. ······························· 6分 (2)由(1)得13n n a +=,所以31n n a =−, ············································· 8分 所以()()()2313131n n S =−+−++−()233333n n =++++− ···························································· 10分13313n n +−=−− ············································································ 12分 133.2n n +−=− ············································································ 13分【解法二】(1)证明:因为132n n a a +=+,所以()113331n n n a a a ++=+=+, ····························································· 2分 因为12a =,所以1130a +=≠,所以10n a +≠, ········································ 4分 所以1131n n a a ++=+, 所以数列{}1n a +是以3为首项,3为公比的等比数列. ······························· 6分 (2)略,同解法一. 16. (15分)已知ABC △的内角,,A B C 的对边分别为,,a b c,且2cos cos cos a C C B =⋅. (1)求角C ;(2)若4a =,b =D 为AB 中点,求CD 的长. 【解法一】(1)因为2cos cos cos a C C B =+⋅, 由正弦定理,得2sin cos cos sin A C B C B C =·············································· 2分()B C =+ ·································································· 4分()πA −A =,······································································ 6分 因为0πA <<,则sin 0A ≠,所以cos C =, ·········································· 7分 由于0πC <<,则π6C =; ···································································· 8分 (2)因为D 为AB 中点,故()12CD CA CB =+, ······································ 10分22111πcos 4426CA CB CA CB =++ ············································ 13分 1113164442=⨯+⨯+ 314=,················································································· 14分 所以CD . ······································································ 15分 【解法二】(1)因为2coscos cos a CC B =⋅,由余弦定理,得2222222cos 22a b c a c b a C ab ac+−+−=··························· 2分 , ···························································· 4分所以cos C =, ················································································ 6分 由于0πC <<,则π6C =; ···································································· 8分 (2)由(1)知,π6ACB ∠=, 在ABC △中,由余弦定理,得2222cos c a b ab ACB =+−∠··································································· 10分 22424=+−⨯ 7=, ··························································································· 11分 故c =, ······················································································· 12分 因为D 为AB 中点,所以cos cos 0ADC BDC ∠+∠=,故222222022AD CD AC BD CD BC AD CD BD CD +−+−+=⨯⨯⨯⨯, ·········································· 13分22222240CD CD +−+−=,故CD . ··········································································· 15分 【解法三】(1)略,同解法一或解法二; (2)由(1)知,π6ACB ∠=, 在ABC △中,由余弦定理,得2222cos c a b ab ACB =+−∠··································································· 10分22424=+−⨯ 7=, ··························································································· 11分故c =, ······················································································· 12分 所以222cos 2b c a A bc+−=2224+−==, ············································································· 13分 在ACD △中,由余弦定理, 得2222cos CD AC AD AC AD A =+−⋅222⎛=+− ⎝⎭⎝314=, ······················································································· 14分故CD . ··········································································· 15分 17. (15分)如图,在四棱锥S ABCD −中,BC ⊥平面SAB ,∥AD BC ,1SA BC ==,SB =,o 45SBA ∠=.(1)求证:SA ⊥平面ABCD ;(2)若12AD =,求平面SCD 与平面SAB 的夹角的余弦值. 【解法一】(1)在△SAB 中, 因为1SA =,o 45SBA ∠=,SB =, 由正弦定理,得sin sin SA SBSBA SAB=∠∠, ········································································· 1分所以1sin 45︒, ······································································ 2分 所以sin 1SAB ∠=,因为0180SAB ︒<∠<︒,所以90SAB ∠=︒,所以SA AB ⊥. ··················································································· 4分 因为BC ⊥平面SAB ,SA ⊂平面SAB ,所以BC SA ⊥, ··················································································· 5分 又BCAB B =,所以SA ⊥平面ABCD ; ········································································· 6分 (2)解:由(1)知SA ⊥平面ABCD ,又,⊂AB AD 平面ABCD ,所以SA AB ⊥,SA AD ⊥,因为BC ⊥平面SAB , ··········································································· 7分 ⊂AB 平面SAB ,所以BC AB ⊥,因为∥AD BC ,所以AD AB ⊥,所以,,SA AD AB 两两垂直. ··································································· 8分 以点A 为原点,分别以AD ,AB ,AS 所在直线为x 轴,y 轴,z 轴建立如图所示的空间直角坐标系, ················································································ 9分 则1(1,1,0),,0,0,2(0,0,1),D S C ⎛⎫ ⎪⎝⎭所以()1,1,1SC =−,1,0,12SD ⎛⎫=− ⎪⎝⎭,设平面SCD 的法向量为1(,,)x y z =n ,则11,,SC SD ⎧⊥⎪⎨⊥⎪⎩n n 即110,10,2SC x y z SD x z ⎧⋅=+−=⎪⎨⋅=−=⎪⎩n n 取2x =,则()12,1,1=−n , ·································································· 11分显然平面SAB 的一个法向量()21,0,0=n , ················································ 12分 所以cos ⋅=⋅121212n n n ,n n n ····································································· 13分==········································································· 14分 所以平面SCD 与平面SAB . ··································· 15分 【解法二】(1)证明:设AB x =,在△SAB 中, 因为1SA =,o 45SBA ∠=,SB =, 由余弦定理,得2222cos SA SB AB SB S AB BA =∠+−⋅, · (1)分 所以212co 5s 4x =+−︒, (2)分所以221x +−=, 所以2210x x −+=,解得1x =. ························································································ 3分 所以2222SA AB SB +==,所以SA AB ⊥. ················································ 4分 因为BC ⊥平面SAB ,SA ⊂平面SAB ,所以BC SA ⊥, ··················································································· 5分 又BCAB B =,所以SA ⊥平面ABCD ; ········································································· 6分 (2)略,同解法一.【解法三】(1)设AB x =,在△SAB 中, 因为1SA =,o 45SBA ∠=,SB =, 由余弦定理,得2222cos SA SB AB SB S AB BA =∠+−⋅, (1)分所以212co 5s 4x =+−︒, ································································ 2分所以221x+−=,所以2210x x−+=,解得1x=. ························································································3分所以2222SA AB SB+==,所以SA AB⊥.················································4分因为BC⊥平面SAB,BC⊂平面ABCD,所以平面ABCD⊥平面SAB;·································································5分又平面ABCD平面SAB AB=,SA AB⊥,SA⊂平面SAB,所以SA⊥平面ABCD;·········································································6分(2)由(1)知SA⊥平面ABCD,过B作BM SA,则BM⊥平面ABCD,又,AB BC⊂平面ABCD,所以BM AB⊥,BM BC⊥,因为BC⊥平面SAB,···········································································7分又⊂AB平面SAB,所以BC AB⊥,所以,,BM BA BC两两垂直.··································································8分以点B为原点,分别以BA,BC,BM所在直线为x轴,y轴,z轴建立如图所示的空间直角坐标系, ················································································9分则1(0,1,0),1,(,0,21,0,1),CS D⎛⎫⎪⎝⎭所以()1,1,1SC=−−,11,,02CD⎛⎫=−⎪⎝⎭,设平面SCD的法向量为1(,,)x y z=n,则11,,SCCD⎧⊥⎪⎨⊥⎪⎩nn即110,10,2SC x y zCD x y⎧⋅=−+−=⎪⎨⋅=−=⎪⎩nn取2y=,则()11,2,1=n, ···································································· 11分显然平面SAB的一个法向量()20,1,0=n, ··············································· 12分所以cos⋅=⋅121212n nn,nn n····································································· 13分=。
(在此卷上答题无效)2023~2024 学年福州市高三年级4月份质量检测数 学 试 题(完卷时间 120 分钟; 满分 150 分)友情提示: 请将所有答案填写到答题卡上!请不要错位、越界答题!一、单项选择题:本题共8小题,每小题5分,共40分.在每小题给出的四个 选项中,只有一项是符合题目要求的.1. 已知集合101M xx= +…,则M =R ð A. {}1x x <−B. {}1x x −…C. {}1x x >−D. {}1x x −…2. 设,a b ∈R ,则“0ab <”是“0a ba b”的 A .充分不必要条件B .必要不充分条件C .充要条件D .既不充分也不必要条件3. 等轴双曲线经过点(3,1)−,则其焦点到渐近线的距离为A .B .2C .4D6. 54(1)(12)x x −+的展开式中2x 的系数为A .14−B .6−C .34D .747. 数列{}n a 共有5项,前三项成等差数列,且公差为d ,后三项成等比数列,且公比为q .若第2项等于2,第1项与第4项的和等于10,第3项与第5项的和等于30,则d q −= A .1 B .2 C .3 D .48. 四棱锥E ABCD −的顶点均在球O 的球面上,底面ABCD 为矩形,平面BEC ⊥平面ABCD ,BC =,1CD CE ==,2BE =,则O 到平面ADE 的距离为A .13B .14C D二、多项选择题:本题共3小题,每小题6分,共18分.在每小题给出的四个选项中,有多项符合题目要求.全部选对的得6分,部分选对的得部分分, 有选错的得0分.9. 在一次射击比赛中,甲、乙两名选手的射击环数如下表,则下列说法正确的是甲乙87 90 96 91 86 90 86 92 87 95A .甲选手射击环数的极差大于乙选手射击环数的极差B .甲选手射击环数的平均数等于乙选手射击环数的平均数C .甲选手射击环数的方差大于乙选手射击环数的方差D .甲选手射击环数的第75百分位数大于乙选手射击环数的第75百分位数 10. 已知函数()()sin 2f x x ϕ=+满足ππ33f x f x+=−,且π()(π)2f f >,则A .1sin 2ϕ=B .1sin 2ϕ=−C .()y f x =的图象关于点13(π,0)12对称D .()f x 在区间π(,π)2单调递减11. 已知函数()(e e )e e x x x x f x ax −−=+−+恰有三个零点123,,x x x ,且123x x x <<,则 A .1230x x x ++= B .实数a 的取值范围为(0,1] C .110ax +>D .31ax a +>三、填空题:本大题共3小题,每小题5分,共15分.12. 若向量(3,4)=−a 在向量b (2,1)=−上的投影向量为λb ,则λ等于__________.13. 倾斜角为π3的直线经过抛物线C :212y x =的焦点F ,且与C 交于A ,B 两点,Q 为线段AB 的中点,P 为C 上一点,则PF PQ +的最小值为__________.14. 如图,六面体111ABCDA C D的一个面ABCD 是边长为2的正方形,111,,AA CC DD 均垂直于平面ABCD ,且11AA =,12CC =,则该六面体的体积等于__________,表面积等于_________.1A四、解答题:本大题共5小题,共77 分.解答应写出文字说明、证明过程或演算步骤.15. (13分)已知数列{}n a 满足12a =,12n n a a n −=+(2n …). (1)求数列{}n a 的通项公式;(2)记数列1{}na 的前n 项和为n S ,证明:1n S <.16. (15分)甲企业生产线上生产的零件尺寸的误差X 服从正态分布2(0,0.2)N ,规定(0.2,0.2)X ∈−的零件为优等品,(0.6,0.6)X ∈−的零件为合格品.(1)从该生产线上随机抽取100个零件,估计抽到合格品但非优等品的个数(精确到整数);(2)乙企业拟向甲企业购买这批零件,先对该批零件进行质量抽检,检测的方案是:从这批零件中任取2个作检测,若这2个零件都是优等品,则通过检测;若这2个零件中恰有1个为优等品,1个为合格品但非优等品,则再从这批零件中任取1个作检测,若为优等品,则通过检测;其余情况都不通过检测.求这批零件通过检测时,检测了2个零件的概率(精确到0.01).(附:若随机变量2~(,)N ξµσ,则()0.6827P µσξµσ−<<+=,(22)0.9545P µσξµσ−<<+=,(33)0.9973P µσξµσ−<<+=)17. (15分)如图,以正方形ABCD 的边AB 所在直线为旋转轴,其余三边旋转120°形成的面围成一个几何体ADF BCE −.设P 是»CE 上的一点,G ,H 分别为线段AP ,EF 的中点.(1)证明:GH ∥平面BCE ;(2)若BP AE ⊥,求平面BPD 与平面BPA 夹角的余弦值.C18. (17分)点P 是椭圆E :22221(0)x y a b a b+=>>上(左、右端点除外)的一个动点,1(,0)F c −,2(,0)F c 分别是E 的左、右焦点.(1)设点P 到直线2:a l x c =的距离为d ,证明2||PF d为定值,并求出这个定值; (2)12PF F △的重心与内心(内切圆的圆心)分别为G ,I ,已知直线IG 垂直于x 轴. (ⅰ)求椭圆E 的离心率;(ⅱ)若椭圆E 的长轴长为6,求12PF F △被直线IG 分成两个部分的图形面积之比的取值范围.19. (17分)记集合{}(),000()()|,()(),,()()f x x D L l x kx b x x D f x l x x D f x l x ∈==+∈∀∈∃∈=R 且…,集合{}(),000()()|,()(),,()()f x x D T l x kx b x x D f x l x x D f x l x ∈==+∈∀∈∃∈=R 且….若(),()f x x D l x L ∈∈,则称直线()y l x =为函数()f x 在D 上的“最佳上界线”;若(),()f x x D l x T ∈∈,则称直线()y l x =为函数()f x 在D 上的“最佳下界线”.(1)已知函数2()f x x x =−+,0()1l x kx =+.若0(),()f x x l x L ∈∈R ,求k 的值; (2)已知()e 1x g x =+.(ⅰ)证明:直线()y l x =是曲线()y g x =的一条切线的充要条件是直线()y l x =是函数()g x 在R 上的“最佳下界线”;(ⅱ)若()ln(1)h x x =−,直接写出集合(),(1,)(),h x x g x x L T ∈+∞∈R I 中元素的个数(无需证明).2023~2024 学年福州市高三年级4月份质量检测参考答案与评分细则一、选择题:本大题考查基础知识和基本运算.每小题5分,满分40分.1.D 2.C 3.A 4.C 5.D 6.B 7.B 8.A二、选择题:本大题考查基础知识和基本运算.每小题6分,满分18分.全部选对的得6分,部分选对的得部分分,有选错的得0分.9.ABC 10.BC 11.ACD三、填空题:本大题考查基础知识和基本运算.每小题5分,满分15分.12.2− 13.8 14.6,22四、解答题:本大题共5小题,共77分.解答应写出文字说明、证明过程或演算步骤.15. 【考查意图】本小题主要考查递推数列与数列求和等基础知识,考查运算求解能力、推理论证能力等;考查分类与整合、化归与转化等思想方法;考查数学运算、逻辑推理等核心素养;体现基础性和综合性.满分13分.解:(1)因为12,2n n a a n n −=+…,所以12n n a a n −−=,···································1分 当2n …时,112211()()()n n n n n a a a a a a a a −−−=−+−++−+L ,所以22242n a n n =+−+++L ,·························································3分 所以(22),22n n n a n +=…,所以2,2n a n n n =+…,··································4分 又因为12a =,···············································································5分 所以2*,n a n n n =+∈N .······································································6分 (2)由(1)可知2*(1),n a n n n n n =+=+∈N ,·············································7分所以()111111n a n n n n ==−++,····························································9分 所以11111223(1)(1)n S n n n n =++++××−+L 1111111122311n n n n =−+−++−+−−+L ,·····································11分 所以111n S n =−+,·········································································12分 又因为1n …,所以1n S <.·································································································13分16.【考查意图】本小题主要考查正态分布、全概率公式、条件概率等基础知识,考查数学建模能力、逻辑思维能力和运算求解能力等,考查分类与整合思想、概率与统计思想等,考查数学建模、数据分析、数学运算等核心素养,体现基础性、综合性和应用性.满分15分. 解:(1)依题意得,0,0.2µσ==,···························································1分所以零件为合格品的概率为(0.60.6)(33)0.9973P X P X µσµσ−<<=−<<+=, ···································································································2分 零件为优等品的概率为(0.20.2)()0.6827P X P X µσµσ−<<=−<<+=,·····3分 所以零件为合格品但非优等品的概率为0.99730.68270.3146P =−=,···········5分 所以从该生产线上随机抽取100个零件,估计抽到合格品但非优等品的个数为1000.314631×≈.·············································································6分 (2)设从这批零件中任取2个作检测,2个零件中有2个优等品为事件A ,恰有1个优等品,1个为合格品但非优等品为事件B ,从这批零件中任取1个检测是优等品为事件C ,这批产品通过检测为事件D ,····························································8分 则D A BC =+,且A 与BC 互斥,·······················································9分 所以()()()P D P A P BC =+·································································10分()()(|)P A P B P C B =+·························································11分221220.68270.68270.31460.6827C C =×+×××21.62920.6827=×,····························································12分所以这批零件通过检测时,检测了2个零件的概率为 ()(|)()P AD P A D P D =···········································································13分 220.68271.62920.6827=× 11.6292= 0.61≈.············································································· 15分答:这批零件通过检测时,检测了2个零件的概率约为0.61.17.【考查意图】本小题主要考查直线与平面平行的判定定理、直线与平面垂直的判定与性质定理、平面与平面的夹角、空间向量、三角函数的概念等基础知识,考査直观想象能力、逻辑推理能力、运算求解能力等,考查数形结合思想、化归与转化思想等,考査直观想象、逻辑推理、数学运算等核心素养,体现基础性、综合性.满分15分.解法一:(1)在正方形ABEF 中,连接AH 并延长,交BE 的延长线于点K ,连接PK .···································································································2分因为,G H 分别为线段,AP EF 中点, 所以HF HE =,所以Rt AFH △≌Rt KEH △,所以AH KH =,·····························4分 所以GH PK ∥.································5分 又因为,GH BCE PK BCE ⊄⊂面面,所以GH BCE ∥面.···········································································7分 (2)依题意得,AB BCE ⊥面,又因为BP BCE ⊂面,所以AB BP ⊥.又因为BP AE ⊥,AB AE A =I ,,AB AE ABEF ⊂面,所以BP ABEF ⊥面,········································································8分 又BE ABEF ⊂面,所以BP BE ⊥,·····················································9分解法二:(1)证明:取BP 的中点Q ,连接,GQ EQ . ·····1分因为,G H 分别为线段,AP EF 的中点, 所以GQ AB ∥,12GQ AB =,····························2分 又因为,AB EF AB EF =∥,所以,GQ HE GQ HE =∥,·································3分所以四边形GQEH 是平行四边形,······················································4分 所以GH QE ∥,··············································································5分 又因为,GH BCE QE BCE ⊄⊂面面,所以GH BCE ∥面.············································································7分 (2)同解法一.····················································································15分所以GH BCE ∥面.············································································7分 (2)同解法一.····················································································15分18.【考查意图】本小题主要考查圆、椭圆的标准方程及简单几何性质,直线与椭圆的位置关系等基础知识,考査直观想象能力、逻辑推理能力、运算求解能力等,考查数形结合思想、化归与转化思想、分类与整合思想等,考査直观想象、逻辑推理、数学运算等核心素养,体现基础性、综合性与创新性.满分17分.解法一:(1)依题意,222b c a +=.··························································1分设00(,)P x y ,则2200221x y a b +=,0ax a −<<,所以2||PF =,所以20||||cPF x a a==−,············································3分又a c >,所以0c a x a >,20a x c >,所以20||c PF a x a =−,20a d x c =−所以0220||c a x PF c a a d a x c−==−,即2||PF d 为定值,且这个定值为ca.··················4分 (2)(ⅰ)依题意,00(,)33x yG ,设直线IG 与x 轴交于点C ,因为IG ⊥x 轴,所以0(,0)3xC ,·······················5分所以001202||||()()333x x FC F C c c x −=+−−=,··········································6分 因为△PF 1F 2的内切圆与x 轴切于点C ,所以121202||||||||3PF PF F C F C x −=−=,·················································7分又因为12||||2PF PF a +=,解得02||3x PF a =−,··········································8分由(1)得20||cPF a x a =−, 所以003x ca x a a −=−,所以椭圆E 的离心率13c e a ==.·························10分(ⅱ)由26a =,得3a =,又13c a =,所以1c =,2228b a c =−=,所以椭圆E 的方程为22198x y +=.······················································11分根据椭圆对称性,不妨设点P 在第一象限或y 轴正半轴上,即003x <…,00y <…, 又1(1,0)F −,2(1,0)F ,所以直线PF 1的方程为00(1)1yy x x =++,设直线IG 与PF 1交于点D ,因为03D x x =,所以000(3)3(1)D y x y x +=+,△F 1CD 的面积1S 与△PF 1F 2的面积S 之比为00200100(3)1(1)233(1)(3)118(1)22x y x x x S S x y ++×++==+××,················································13分令2(3)()18(1)x f x x +=+(03x <…),则2(3)(1)(1))(18x x x f x −′++=,当[0,1)x ∈,()0f x ′<,当(1,3)x ∈,()0f x ′>, 所以函数()f x 在[0,1)单调递减,在(1,3)单调递增.又因为1(0)2f =,4(1)9f =,1(3)2f =,所以()f x 的值域是41[,]92,所以14192S S ……,··········································································15分所以11415S S S −……,·······································································16分 根据对称性,△PF 1F 2被直线IG 分成两个部分的图形面积之比的取值范围是45[,54.········17分解法二:(1)同解法一···········································································4分(2)(ⅰ)依题意,00(,33x yG ,设直线IG 与x 轴交于点C ,因为IG ⊥x 轴,所以0(,0)3xC ,·······················5分所以001202||||()()333x x FC F C c c x −=+−−=,··········································6分 因为△PF 1F 2的内切圆与x 轴切于点C ,所以121202||||||||3PF PF F C F C x −=−=,·················································7分又因为12||||2PF PF a +=,得0102||,3||.3x PF a x PF a=+ =− ···········································8分所以00,3,3x a x a =+=−两式平方后取差,得00443cx ax =对任意0x 成立, 所以椭圆E 的离心率13c e a ==.························································10分(ⅱ)同解法一···················································································17分 解法三:(1)同解法一···········································································4分(2)(ⅰ)依题意,00(,33x y G ,因为IG ⊥x 轴,设点I 坐标为0(,)3xt .··········5分可求直线1PF 方程为00()yy x c x c=++,则点I 到直线1PF 的||t =,·································6分即()222200000()()()3x y c t x c t y x c +−+=++ ,化简得22000002()()()033x xy t t c x c y c +++−+=,①同理,由点I 到直线2PF 的距离等于||t ,可得22000002()()()033x xy t t c x c y c +−−−−=,②············································7分 将式①−式②,得00084233t cx y cx ⋅=⋅,则04y t =.·····································8分将04yt =代入式①,得2200001()()()016233y xx c x c c +++−+=, 化简得220022198x y c c +=,得229c a =,所以椭圆E 的离心率13c e a ==.························································10分(ⅱ)同解法一···················································································17分19.【考查意图】本小题主要考查集合、导数、不等式等基础知识,考查逻辑推理能力、直观想象能力、运算求解能力和创新能力等,考查函数与方程思想、化归与转化思想、分类与整合思想、数形结合思想等,考查数学抽象、逻辑推理、直观想象、数学运算等核心素养,体现基础性、 综合性与创新性.满分17分. 解:(1)依题意,因为0(),()f x x l x L ∈∈R ,所以2,1x x x kx ∀∈−++R …,且0x R ,20001x x kx −+=+,····················1分 令2()(1)1x x k x φ=−+−−,()214k ∆=−−, 则()0x φ…,且0()0x φ= ,所以0,0,∆ ∆ ……所以0∆= ,···································································3分即()2140k −−=,解得3k =或1−.··············································································4分(2)(ⅰ)先证必要性.若直线()y l x =是曲线()y g x =的切线,设切点为()00,e 1x x +, 因为()e x g x ′=,所以切线方程为()000e 1e ()x x y x x −+=−,即()000e (1)e 1x x l x x x =+−+(*).························································5分 一方面,()()00g x l x =,所以000,()()x g x l x ∃∈=R ,································6分。
福州市高三数学质量检测试题答案1 二、13. 3 16. 4 13 6 三、 1 17.解:(理)T 1 1 1 . ——i Z 1Z 2 2 4 • cos(- a )+ i sin(- a )+cos(- 3 )+ i sin(- 3)= 1 1 . -—i 2分 3 ) i =—1 . —i2 4• (cos a +cos 3 )-(sin a +sinc 1 xosa +cos 3 =— 2 4 ① 21 J sin a +sin 3 =— ② 4 分4 ①2 2 +②得:2+2cos( a -3 )= —即 cos( a - 3 )=27 6分1632③由①得:2cos ---------- c os 2 2 21由②得:2sin ---------- c os ---------- =2 2 41-10分2④十③得:tg = 2 1 1 _41 45 12 分(文)(I )由 y =2X +a 1• f (x )=log 2( x - a ) 定义域为{x | x > a } 2 x =y -a x =log 2(y -a ) 2 分4 分5 分(n )由已知得 1=log 2( x +a -a )且 2=log 2(x -2 a ) 即log 2X = 1..log 2( x -2 a )=22a 43 则PQ 的中点R 坐标是(2 , ) 12 分 218.证明:(I )取 PD 中点 Q 连 EQ AQ 则 T QB/ CD CD// AB • QB/ AB , 1又 QE=丄 CD=AB2• ABEQi 平行四边形,• BE// AQ又AQ 平面PAD• B E//平面PAD 3 分 ••• R1 , 1)、Q3, 2). (n ) T PA!底面 ABCD • CDL PA 又 CDL AD• CDL 平面 PAD • AQL CD若PAAD •/ Q 为PD 中点••• AQL PD••• AQL 平面 PCD•/ BE// AQ • BEL 平面 PCD 7 分(川)连结AC 取AC 的中点G,连EG EG PA•/ PA!平面 ABCD •- EGL 平面 ABCD过G 作GH L BD 连E H ,则E H 丄BD•••/ EH 侥二面角E- BD- C 的平面角 10 分设 AB=1 ,贝U PA=AD=DC=2AB=2.• E(=1P A=1 , DB= , AD 2 AB 2 5 ,2 DC AC又•••/ CAB :/ ACD 2, AB AG1• △ AC EA ABG • BG — AD=1, / ABG / ADC 90°2 •. BG// AD / GE H=Z ADB ••△ ABD^A H BG• HG BGAB BD , ••• HCA B^GDB• tg EHG 更 HG 5. 12 分1 219.解:(I ) ••• S= —(n 2-n +2) • a=S=1; 2 当n 》2时, c c 1 2 1 2 a n —S n - S-1 — ( n - n +2)- [( n -1) -( n -1)+2 ] =n -1 2 一 • - 1(n 1) …a n — n 1(n 2) 1 m-( n 》2) 2m 1 • b n —b 1 + (b 2-b 1)+ ( b 3- b 2)+ …+( b n - b n-1) d 1 1 1 c 1 —1+ + 2 - 2 22 2 n 1 2门 1 又 b 1 = 1 且 b n - b n-1 (n )(i)当 n —1 时,T a 1—1,b 1—1 • a>5b 1 不成立; (ii)当n 》2时,若a n > 5b n 恒成立1 即n -1 > 5(2-------- )恒成立 2“ 1 5 n > 11- 一7恒成立 11 2* 1只须 •••令n o —11,则当 n 》11时,恒有 a n > 5b 1 -P 7,16 p 20 20.解:(I )q — 4 1P 6,20 P 25由于 n 》2时,11- 12分 3分 壬-v 112* 1(n )设月利润为 W 万元),则1 (-p 7)( p 16) 6.8,16 V=(p -16)= 41 ( p 6)( p 16) 6.8,20 5 1 2当 16< p w 20, W =- (p -22) +4当p =20时,Wa= 7 分1 2当 20v p w 25, W =- — (p -23) +35当 p =23 时,Wa=3•••当售价定为23元/件时,月利润最多为 3万元 9 分 (川)设最早n 个月后还清转让费,则3n > 58, n 》20, •企业乙最早可望 20个月后还清转让费122 2 21. 解:(I )设 A ( B (疽,yj 1 分2m2m•••/ AQPZ BQP• tg AQP tg BQP y 2yyw 1+y 2)=-8 my 计y 2) T I 不垂直于x 轴,.y 1 +y 2* 0• y 1y 2=-8m 4 分••• O 点是 PQ 的中点,且 Q -4 , 0) ,• R4 , 0)k AP =4 宜4 2m • k AF =k BP••• AP 与 BP 都过P 点 (n )假设I '存在,设其方程为 x =n2设 A (X 1,y 1)则屮=4X 1•••以AP 为直径的圆的圆心 C ( 一4丿1)2 ' 2•直线I '被圆截得的弦长为■ 12 2 X [ 4 2 2 右(X1 4) y1 (丁 n) 10 分 p 20p 25 2 y 1 4 2m2 y 2 2m 1 又 k AF = y比4 2m 8my 2 2my 2 2my 2 y 2 8m 孕匚6分y 2 8m • A 、P 、B 三点共线J 22 (n 3)x i 4n n •••当n =3时,弦长为定值 2 . 3•••存在直线l ' : x =3满足要求 12 分22. 解:(I )f (x )的反函数是 f -1(x )=log 2(x - a )( x > a )••• P 、Q R 是f -1(x )图象上不同三点• y i =log 2X , y 2=log 2( x - a ), y 3=l 2 分•••是不同三点,• a z 0(即x 丰2) 3 分已知 屮、y 2、y 3成等差数列,即 y 1+y 3=2y 2• 1+log 2x =2log 2(x -a ),即 log 2 2x =log 2( x - a ) x - a =、2x x > 0 且 x > a a =x - 2x ( x > 0 且 x 工2) ① 5 分2x 2 又等价于(x a) 2x ② x 3 ③方程②等价于x 2-2( a +1)x +a 2=0④ 2 2A = : 2(a +1): -4a =8a +4 8 分1 、 11°当a =- 时,A =0,方程④仅有一个实数解 x = 且满足③2 21• a =--满足①有惟一解21 、2°当a >—— 时,A > 0,方程②有二个相异实数解 2X 1=a +1 +-:_:2a 1 , X 2=a +1- 2a 1又X 1=a +1+. 2a 1 > a • X 1> a 满足条件③• X 1是方程①的解 11 分要使方程①有惟一解,则 X 2不能是①的解• X 2=a +1- 2a 1 < a____(2a 1) 1 2a 1 > 1 1 a > 0.a 2,1■/ a z 0 • a >0 综合1 ° ,2 ° , a 的取值范围是 a =- 或a >0 142(n )等量关系①等价于 (x a)2x ax 0。
2023—2024学年福州市高三年级4月末质量检测数学试题(完卷时间120分钟;满分150分)友情提示:请将所有答案填写到答题卡上!请不要错位、越界答题!一、选择题:本题共8小题,每小题5分,共40分.在每小题给出的四个选项中,只有一项是符合题目要求的.1.已知集合101M x x ⎧⎫=≤⎨⎬+⎩⎭,则R M =ð()A.{}1x x <- B.{}1x x ≤- C.{}1x x >- D.{}1x x ≥-【答案】D 【解析】【分析】先解不等式再利用补集运算即可求解.【详解】由101x ≤+得10x +<,即1x <-,所以{}1M x x =<-,于是{}R 1M x x =≥-ð.故选:D.2.设a ,b ∈R ,则“0ab <”是“0a ba b+=”的()A.充分不必要条件B.必要不充分条件C.充要条件D.既不充分也不必要条件【答案】C 【解析】【分析】根据充要条件的概念即可求解.【详解】当0ab <时,00a b >⎧⎨<⎩或0a b <⎧⎨>⎩,则0a b a b +=,即充分性成立;当0a b a b +=时,0b ba a =->,则0ab <,即必要性成立;综上可知,“0ab <”是“0a ba b+=”的充要条件.故选:C.3.等轴双曲线经过点()3,1-,则其焦点到渐近线的距离为()A. B.2C.4D.【答案】A 【解析】【分析】由题意,先求出等轴双曲线的方程,得到焦点坐标和渐近线方程,再利用点到直线的距离公式进行求解即可.【详解】因为该曲线为等轴双曲线,不妨设该双曲线的方程为22221(0)x y a a a-=>,因为等轴双曲线经过点(3,1)-,所以22911a a-=,解得28a =,则22216c a a =+=,所以该双曲线的一个焦点坐标为(4,0)F ,易知该双曲线的一条渐近线方程为y x =,则点(4,0)F 到直线y x =的距离d ==.故选:A .4.已知1sin 44πα⎛⎫+=⎪⎝⎭,则sin 2α的值为() A.78B.158C.158-D.78-【答案】D【解析】【分析】先利用和角公式展开1sin 44πα⎛⎫+= ⎪⎝⎭,平方可求sin 2α.【详解】1sin cos 4224πααα⎛⎫+=+=⎪⎝⎭平方可得11(1sin 2)216α+=,所以7sin 28α=-,故选D.【点睛】本题主要考查倍角公式,熟记公式是求解关键,题目较为简单,侧重考查数学运算的核心素养.5.已知非零复数z 满足1i z z -=-,则zz=()A.1 B.1- C.iD.i-【答案】D 【解析】【分析】设()i ,z a b a b =+∈R ,利用条件证明a b =,再代入zz化简即可.【详解】设()i ,z a b a b =+∈R ,则由1i z z -=-知()1i 1i a b a b -+=+-.从而()()222211a b a b -+=+-,展开即得a b =.由z 非零,知0a b =≠,故()()()2i 1i i 1i 2i i i 1i 1i 1i 2i a z a b b a z a b b-----======-+++-+.故选:D.6.()()54112x x -+的展开式中2x 的系数为()A.14- B.6- C.34D.74【答案】B 【解析】【分析】直接利用二项式的展开式以及组合数的应用求出结果.【详解】5(1)x -的展开式为15C (1)(0rrrr T x r +=⋅-⋅=,1,2,3,4,5),4(12)x +的展开式14C 2(0k k k k T x k +=⋅⋅=,1,2,3,4),当0r =,2k =时,2x 的系数为224C 224⋅=;当1r =,1k =时,2x 的系数为54240-⨯⨯=-;当2r =,0k =时,2x 的系数为25C 10=,故2x 的系数为2410406+-=-.故选:B .7.数列{}n a 共有5项,前三项成等差数列,且公差为d ,后三项成等比数列,且公比为q .若第2项等于2,第1项与第4项的和等于10,第3项与第5项的和等于30,则d q -=()A.1 B.2 C.3D.4【答案】B 【解析】【分析】结合等差、等比数列的概念利用第二项写出剩下四个项,进而列方程组即可求解.【详解】由根据题意得,该数列的项为()()22,2,2,2,2d d d q d q -+++,又()()222102230d d q d d q ⎧-++=⎪⎨+++=⎪⎩,即26213021d q d q ⎧+=⎪-⎪⎨⎪+=⎪+⎩,解得24q d =⎧⎨=⎩或31q d =⎧⎨=⎩.于是2d q -=.故选:B.8.四棱锥E ABCD -的顶点均在球O 的球面上,底面ABCD 为矩形,平面BEC ⊥平面ABCD,BC =,1CD CE ==,2BE =,则O 到平面ADE 的距离为()A.13B.14C.24D.58【答案】A 【解析】【分析】根据线面关系可证得AB ⊥平面BEC ,BE CE ⊥,将四棱锥E ABCD -补成长方体111AD DA BECB -,确定球心的位置,再建立空间直角坐标系,求解平面ADE 的法向量,利用空间向量的坐标运算计算O 到平面ADE 的距离即可.【详解】因为平面BEC ⊥平面ABCD ,交线为BC ,又底面ABCD 为矩形,则AB BC ⊥,因为AB ⊂平面ABCD ,所以AB ⊥平面BEC ,则,AB CE AB EB ⊥⊥,又BC =,1CD CE ==,2BE =,所以222BE CE BC +=,则BE CE ⊥,如图,将四棱锥E ABCD -补成长方体111AD DA BECB -,若四棱锥E ABCD -的顶点均在球O 的球面上,则长方体111AD DA BECB -的顶点均在球O 的球面上,O 为体对角线11D B 中点,如图,以E 为原点,1,,EC EB ED 所在直线为,,x y z轴建立空间直角坐标系,则()()()()()110,2,1,1,0,1,0,0,0,0,0,1,1,2,0A D E D B ,故11,1,22O ⎛⎫⎪⎝⎭,设平面ADE 的法向量为(),,n x y z =,又()()0,2,1,1,0,1EA ED == ,12020n EA y z y z n ED x z x z⎧⎧⋅=+==-⎪⎪⇒⎨⎨⋅=+=⎪⎪⎩=-⎩ ,令2z =,所以()2,1,2n =-- ,又11,1,22EO ⎛⎫= ⎪⎝⎭ ,则O 到平面ADE的距离为13EO n n ⋅==.故选:A.【点睛】方法点睛:解决与球相关的切、接问题,其通法是作出截面,将空间几何问题转化为平面几何问题求解,其解题思维流程如下:(1)定球心:如果是内切球,球心到切点的距离相等且为球的半径;如果是外接球,球心到接点的距离相等且为半径;(2)作截面:选准最佳角度做出截面(要使这个截面尽可能多的包含球、几何体的各种元素以及体现这些元素的关系),达到空间问题平面化的目的;(3)求半径下结论:根据作出截面中的几何元素,建立关于球的半径的方程,并求解.或者采用补形法,利用规则图形的外接球位置确定所求外接球球心的位置.二、选择题:本题共3小题,每小题6分,共18分.在每小题给出的选项中,有多项符合题目要求.全部选对的得6分,部分选对的得部分分,有选错的得0分.9.在一次射击比赛中,甲、乙两名选手的射击环数如下表,则下列说法正确的是()甲乙87909691869086928795A.甲选手射击环数的极差大于乙选手射击环数的极差B.甲选手射击环数的平均数等于乙选手射击环数的平均数C.甲选手射击环数的方差大于乙选手射击环数的方差D.甲选手射击环数的第75百分位数大于乙选手射击环数的第75百分位数【答案】ABC 【解析】【分析】通过极差、平均数、方差、第75百分位数的计算即可求解.【详解】甲选手射击环数从小到大排列:86,87,90,91,96,则甲选手射击环数的:极差等于968610-=;平均数等于()18687909196905⨯++++=;方差等于()()()()()2222218690879090909190969012.45⎡⎤⨯-+-+-+-+-=⎣⎦;第75百分位数等于91.乙选手射击环数从小到大排列:86,87,90,92,95,则乙选手射击环数的:极差等于95869-=;平均数等于()18687909295905⨯++++=;方差等于()()()()()2222218690879090909290959010.85⎡⎤⨯-+-+-+-+-=⎣⎦;第75百分位数等于92.综上可知,ABC 选项正确,D 选项错误.故选:ABC.10.已知函数()()sin 2f x x ϕ=+满足()()33ππ+=-f x f x,且()ππ2f f ⎛⎫> ⎪⎝⎭,则()A.1sin 2ϕ=B.1sin 2ϕ=-C.()y f x =的图象关于点13π,012⎛⎫⎪⎝⎭对称 D.()f x 在区间π,π2⎛⎫⎪⎝⎭单调递减【答案】BC 【解析】【分析】由已知结合正弦函数的对称性可先求出ϕ,即可判断A ,B ;然后结合正弦函数的对称性及单调性检验选项C ,D 即可判断.【详解】因为函数()sin(2)f x x ϕ=+满足()()33ππ+=-f x f x,所以()f x 的图象关于π3x =对称,则2πππ32k ϕ+=+,Z k ∈,则6πkπϕ=-,Z k ∈,所以π()sin(2)6f x x =-或5π()sin(2)6f x x =+,因为π((π)2f f >,所以π2π6n ϕ=-,Z n ∈,1sin 2ϕ=-,A 错误,B 正确;则π()sin(2)6f x x =-,13π(sin 2π012f ==,即()f x 的图象关于点13(π,0)12对称,C 正确;当ππ2x <<时,5ππ11π2666x <-<,因为sin y t =在5π(6,11π6上不单调,D 错误.故选:BC .11.已知函数()()e eee xxxx f x ax --=+-+恰有三个零点1x ,2x ,3x ,且123x x x <<,则()A.1230x x x ++=B.实数a 的取值范围为(]0,1C.110ax +>D.31ax a +>【答案】ACD 【解析】【分析】利用()f x 的奇偶性可判断A 选项;将函数的零点问题转化为函数图像的交点问题,再利用导数和基本不等式确定切线斜率的取值范围,进而得实数a 的取值范围,即可判断B 选项;由112122e1e 1x xax +=+来可判断C 选项;由32321e 1x ax =-+得323121e 1x a x ⎛⎫=- ⎪+⎝⎭,进而31ax a +>等价于323e 210x x -->,令()()2=e210xh x x x -->,用导数证明()0h x >,即可判断D 选项.【详解】函数()()e eee xxxx f x ax --=+-+定义域为R ,()()()()()e e e e e e e e x x x x x x x xf x a x ax f x ----⎡⎤-=-+-+=-+-+=-⎣⎦,所以()f x 是奇函数,则()00f =,又因为()f x 有三个零点且123x x x <<,()()()1230f x f x f x ===,所以13x x =-,20x =,即1230x x x ++=,故A 选项正确;()()e eee0xxxxf x ax --=+-+=,得222e e e 121e e e 1e 1x x x x x x xax --=--==-+++,令()221e 1xg x =-+,则()()2224e 0e 1xxg x =>+',所以()f x 在R 上增函数,要使函数()f x 有3个零点,y ax =与()y g x =的图象有3个交点,如图:又()()()2222222224e 4e 411e 1e 2e 1e 2e xxx xx x x g x ===≤=+++++',当且仅当0x =时取等号,即()01g x <'≤,所以01a <<,故B 错误;111212222e 1110e 1e 1x x x ax ⎛⎫+=-+=> ⎪++⎝⎭,故C 选项正确;由32321e 1x ax =-+得323121e 1x a x ⎛⎫=- ⎪+⎝⎭,又30x >,要使333223212111e 1e 1x x ax a x ⎛⎫+=-+-> ⎪++⎝⎭成立,则323e 210x x -->成立,令()()2=e210xh x x x -->,()()()2=2e 100x h x x -'>>,所以()h x 在()0,∞+单调递增,则()()0=0h x h >,于是323e210x x -->,则31ax a +>,故D 正确.故选:ACD.【点睛】方法点睛:已知函数有零点(方程有根)求参数值(取值范围)常用的方法:(1)直接法:直接求解方程得到方程的根,再通过解不等式确定参数范围;(2)分离参数法:先将参数分离,转化成求函数的值域问题加以解决;(3)数形结合法:先对解析式变形,进而构造两个函数,然后在同一平面直角坐标系中画出函数的图象,利用数形结合的方法求解.三、填空题:本题共3小题,每小题5分,共15分.12.若向量()3,4a =- 在向量()2,1b =- 上的投影向量为b λ,则λ等于______.【答案】2-【解析】【分析】根据投影向量的公式运算即可得答案.【详解】向量a 在向量b上的投影向量为2a b b b⋅ ,所以()()()223,42,164252,1a b b λ-⋅-⋅--====--.故答案为:2-.13.倾斜角为π3的直线经过抛物线C :212y x =的焦点F ,且与C 交于A ,B 两点,Q 为线段AB 的中点,P 为C 上一点,则PF PQ +的最小值为______.【答案】8【解析】【分析】由题意,根据给定条件,求出点Q 的横坐标,再借助抛物线的定义求解作答.【详解】易知抛物线2:12C y x =的焦点(3,0)F ,准线3x =-,直线AB的方程为3)y x =-,联立23)12y x y x⎧=-⎪⎨=⎪⎩,消去y 并整理得21090x x -+=,不妨设1(A x ,1)y ,2(B x ,2)y ,由韦达定理得1210x x +=,此时线段AB 的中点Q 的横坐标5Q x =,过P 作准线3x =-的垂线,垂足为D ',过Q 作准线3x =-的垂线,垂足为D ,由抛物线的定义可得5382Q pPF PQ PD PQ QD QD x +=+≥≥+='+'==||||PF PQ +取得的最小值为8.故答案为:8.14.如图,六面体111ABCDA C D 的一个面ABCD 是边长为2的正方形,1AA ,1CC ,1DD 均垂直于平面ABCD ,且11AA =,12CC =,则该六面体的体积等于________,表面积等于______.【答案】①.6②.22【解析】【分析】根据1AA ,1CC ,1DD 均垂直于平面ABCD ,所以111////AA CC DD ,在1DD 上取1DM AA =,连接1,A M MC ,从而根据线线平行可得故1ABA DCM -为三棱柱,111BCC A MD -为三棱柱,根据柱体体积公式即可得该六面体的体积,根据几何体外表面的线线关系结合勾股定理、余弦定理、三角形面积公式、梯形面积公式、正方形面积公式,即可得几何体的表面积.【详解】如图,在1DD 上取1DM AA =,连接1,A M MC ,因为1AA ,1CC ,1DD 均垂直于平面ABCD ,所以111////AA CC DD ,则11,AA AD AA DC ⊥⊥,因为正方形ABCD ,所以AD DC ⊥,又,,AD DC D AD DC =⊂ 平面11A ADD ,所以DC ⊥平面11A ADD ,由1DM AA =可得四边形1AA MD 为平行四边形,所以11//,AD A M AD A M =,因为面ABCD 为正方形,则//,AD BC AD BC =,所以11//,BC A M BC A M =,则四边形1A MCB 为平行四边形,所以11//,A B MC A B MC =,又1A B ⊄平面11DCC D ,MC ⊂平面11DCC D ,所以1//A B 平面11DCC D ,因为平面11DCC D 平面11111A BC D C D =,则111//A B C D ,所以四边形11MD C C 为平行四边形,所以112MD C C ==,故1ABA DCM -为三棱柱,111BCC A MD -为三棱柱,则该六面体的体积1111ABA CDM BCC A MD V V V --=+=1111212222622ABA BCC S BC S DC ⋅+⋅=⨯⨯⨯+⨯⨯⨯= ;如图,连接1,BD D B ,又1A B ===,11A D ===,BD ==所以1BD ==,则在四边形111A BC D中,由余弦定理得22211111111110cos 210A B A D BD D A B A B A D +-∠===-⋅,所以11sin 10D A B ∠==,则11111111sin 610A BC D S AB A D D A B =⋅⋅∠== ,该六面体的表面积111111111ABA BCC A BCD ABCDA ADD DCC D S S S S S S S =+++++ 四边形四边形()()11112122132232622222222=⨯⨯+⨯⨯+⨯+⨯+⨯+⨯++⨯=.故答案为:6;22.【点睛】关键点点睛:解决本题的关键是确定六面体的线线关系.关于求几何体的体积,要注意分割与补形.将不规则的几何体通过分割或补形将其转化为规则的几何体求解.四、解答题:本题共5小题,共77分.解答应写出文字说明、证明过程或演算步骤.15.已知数列{}n a 满足12a =,12n n a a n -=+(2n ≥).(1)求数列{}n a 的通项公式;(2)记数列1n a ⎧⎫⎨⎬⎩⎭的前n 项和为n S ,证明:1n S <.【答案】(1)2n a n n =+,*n ∈N ;(2)证明见解析.【解析】【分析】(1)根据给定条件,利用累加法,结合等差数列前n 项和公式求解即得.(2)利用裂项相消法求和即可得证.【小问1详解】数列{}n a 中,当2n ≥时,12n n a a n -=+,即12n n a a n --=,则12112312()()()()n n n n n a a a a a a a a a a ---=--⋅⋅⋅+--++++()()2222462222n n n a n n n n +=+++⋅⋅⋅+-+==+,而12a =满足上式,所以数列{}n a 的通项公式是2n a n n =+,*n ∈N .【小问2详解】由(1)知()21n a n n n n =+=+,*n ∈N ,则()111111n a n n n n ==-++,因此()()1111122311n S n n n n =++⋅⋅⋅++⨯⨯-+1111111111223111n n n n n =-+-+⋅⋅⋅+-+-=--++,而1n ≥,则1111n -<+,所以1n S <.16.甲企业生产线上生产的零件尺寸的误差X 服从正态分布()20,0.2N ,规定()0.2,0.2X ∈-的零件为优等品,()0.6,0.6X ∈-的零件为合格品.(1)从该生产线上随机抽取100个零件,估计抽到合格品但非优等品的个数(精确到整数);(2)乙企业拟向甲企业购买这批零件,先对该批零件进行质量抽检,检测的方案是:从这批零件中任取2个作检测,若这2个零件都是优等品,则通过检测;若这2个零件中恰有1个为优等品,1个为合格品但非优等品,则再从这批零件中任取1个作检测,若为优等品,则通过检测;其余情况都不通过检测.求这批零件通过检测时,检测了2个零件的概率(精确到0.01).(附:若随机变量()2,N ξμσ,则()0.6827P μσξμσ-<<+=,()220.9545P μσξμσ-<<+=,()330.9973P μσξμσ-<<+=)【答案】(1)约31个(2)约为0.61【解析】【分析】(1)利用正态分布的对称性即可求解;(2)利用条件概率求解即可.【小问1详解】依题意得,0μ=,0.2σ=,所以零件为合格品的概率为()()0.60.6330.9973P X P X μσμσ-<<=-<<+=,零件为优等品的概率为()()0.20.20.6827P X P X μσμσ-<<=-<<+=,所以零件为合格品但非优等品的概率为0.99730.68270.3146P =-=,所以从该生产线上随机抽取100个零件,估计抽到合格品但非优等品的个数为1000.314631⨯≈.【小问2详解】设从这批零件中任取2个作检测,2个零件中有2个优等品为事件A ,恰有1个优等品,1个为合格品但非优等品为事件B ,从这批零件中任取1个检测是优等品为事件C ,这批产品通过检测为事件D ,则D A BC =+,且A 与BC 互斥,所以()()()()()()P D P A P BC P A P B P C B=+=+221222C 0.6827C 0.68270.31460.6827 1.62920.6827=⨯+⨯⨯⨯=⨯,所以这批零件通过检测时,检测了2个零件的概率为22()0.68271(|)0.61() 1.62920.6827 1.6292P AD P A D P D ===≈⨯.答:这批零件通过检测时,检测了2个零件的概率约为0.61.17.如图,以正方形ABCD 的边AB 所在直线为旋转轴,其余三边旋转120°形成的面围成一个几何体ADF BCE -.设P 是CE 上的一点,G ,H 分别为线段AP ,EF 的中点.(1)证明://GH 平面BCE ;(2)若BP AE ⊥,求平面BPD 与平面BPA 夹角的余弦值.【答案】(1)证明见解析(2【解析】【分析】(1)证法一:在正方形ABEF 中,连接AH 并延长,交BE 的延长线于点K ,连接PK ,通过证明Rt Rt AFH KEH ≌△△可得GH PK ∥,进而利用线面平行的判定定理即可证明;证法二:取BP 的中点Q ,连接GQ ,EQ ,通过证明四边形GQEH 是平行四边形可得GH QE ∥,进而利用线面平行的判定定理即可证明;证法三:取AB 的中点I ,连接G I ,HI ,利用面面平行的判定定理证明平面//GIH 平面BCE ,从而即可得证//GH 平面BCE .(2)首先通过线面垂直的判定定理证明BP ⊥平面ABEF 可得BP BE ⊥,然后建立空间直角坐标系,利用向量法可求平面BPD 与平面BPA 夹角的余弦值.【小问1详解】证法一:在正方形ABEF 中,连接AH 并延长,交BE 的延长线于点K ,连接PK .因为G ,H 分别为线段AP ,EF 中点,所以HF HE =,所以Rt Rt AFH KEH ≌△△,所以AH KH =,所以GH PK ∥.又因为GH ⊄平面BCE ,PK ⊂平面BCE ,所以//GH 平面BCE .证法二:取BP 的中点Q ,连接GQ ,EQ ,因为G ,H 分别为线段AP ,EF 的中点,所以//GQ AB ,12GQ AB =,又因为//AB EF ,AB EF =,所以GQ HE ∥,GQ HE =,所以四边形GQEH 是平行四边形,所以GH QE ∥,又因为GH ⊄平面BCE ,QE ⊂平面BCE ,所以//GH 平面BCE .证法三:取AB 的中点I ,连接G I ,HI .因为G ,H 分别为线段AP ,EF 的中点,所以GI BP ∥,HI EB ∥,又因为GI ⊄平面BCE ,BP ⊂平面BCE ,所以//GI 平面BCE .因为HI ⊄平面BCE ,BE ⊂平面BCE ,所以//HI 平面BCE .又因为GI HI I ⋂=,GI ⊂平面GIH ,HI ⊂平面GIH ,所以平面//GIH 平面BCE ,又因为GH Ì平面GIH ,所以//GH 平面BCE .【小问2详解】依题意得,AB ⊥平面BCE ,又因为BP ⊂平面BCE ,所以AB BP ⊥.又因为BP AE ⊥,AB AE A = ,AB ,AE ⊂平面ABEF ,所以BP ⊥平面ABEF ,又BE ⊂平面ABEF ,所以BP BE ⊥,所以BP ,BE ,BA 两两垂直.以B 为原点,BP ,BE ,BA 所在直线分别为x ,y ,z轴建立空间直角坐标系,如图所示.不妨设1AB =,30BCP ∠= ,则()1,0,0P ,31,,122D ⎛⎫- ⎪ ⎪⎝⎭,()1,0,0BP =,31,,122BD ⎛⎫=- ⎪ ⎪⎝⎭,设平面BPD 的法向量为(),,m x y z = ,则0,0,BP m BD m ⎧⋅=⎪⎨⋅=⎪⎩即031022x x y z =⎧-+=⎩,取2y =,得0x =,1z =,所以平面BPD 的一个法向量是()0,2,1m =,又平面BPA 的一个法向量为()0,1,0n =.设平面BPD 与平面BPA 的夹角为θ,则25cos cos ,5m n m n m n θ⋅====.所以平面DBP 与平面BPA.18.点P 是椭圆E :22221x y a b+=(0a b >>)上(左、右端点除外)的一个动点,()1,0F c -,()2,0F c 分别是E 的左、右焦点.(1)设点P 到直线l :2a x c =的距离为d ,证明2PF 为定值,并求出这个定值;(2)12PF F △的重心与内心(内切圆的圆心)分别为G ,I ,已知直线IG 垂直于x 轴.(ⅰ)求椭圆E 的离心率;(ⅱ)若椭圆E 的长轴长为6,求12PF F △被直线IG 分成两个部分的图形面积之比的取值范围.【答案】(1)证明见解析,定值为ca(2)(ⅰ)13;(ⅱ)45,54⎡⎤⎢⎥⎣⎦【解析】【分析】(1)由两点间距离公式(结合点P 在椭圆上)、点到直线距离公式表示出2,PF d ,两式相比即可得解;(2)(ⅰ)解法一:一方面由(1)得20cPF a x a =-,另一方面结合已知以及椭圆定义得023x PF a =-,对比两式即可得解;解法二:利用已知以及椭圆定义得12,PF PF 的一种表达式,另外结合两点间距离公式也可以分别表示12,PF PF ,从而平方后作差即可得解;解法三:表示出12,PF PF 方程,根据题意设出内心坐标,结合点到直线距离公式以及内切圆性质即可得解;(ⅱ)先求出椭圆方程,然后求得1FCD 的面积1S 与12PF F △的面积S 之比的表达式结合导数即可求出其范围,进一步即可得解.【小问1详解】依题意,222b c a +=.设()00,P x y ,则2200221x y a b+=,0a x a -<<,所以2PF =所以20c PF x a a==-,又a c >,所以0c a x a >,20ax c >,所以20c PF a x a =-,20a d x c=-所以0220ca x PF c a a d a x c-==-,即2PF 为定值,且这个定值为c a .【小问2详解】(ⅰ)解法一:依题意,00,33x y G ⎛⎫ ⎪⎝⎭,设直线IG 与x 轴交于点C ,因为IG x ⊥轴,所以0,03x C ⎛⎫⎪⎝⎭,所以001202333x x F C F C c c x ⎛⎫⎛⎫-=+--=⎪ ⎪⎝⎭⎝⎭,因为12PF F △的内切圆与x 轴切于点C ,所以1212023PF PF F C F C x -=-=,又因为122PF PF a +=,解得023x PF a =-由(1)得20cPF a x a =-,所以003x c a x a a -=-,所以椭圆E 的离心率13c e a ==.解法二:依题意,00,33x y G ⎛⎫⎪⎝⎭,设直线IG 与x 轴交于点C ,因为IG x ⊥轴,所以0,03x C ⎛⎫⎪⎝⎭,所以001202333x x F C F C c c x ⎛⎫⎛⎫-=+--=⎪ ⎪⎝⎭⎝⎭,因为12PF F △的内切圆与x 轴切于点C ,所以1212023PF PF F C F C x -=-=,又因为122PF PF a +=,得0102,3,3x PF a x PF a ⎧=+⎪⎪⎨⎪=-⎪⎩所以0,3,3x a x a =+=-两式平方后作差,得00443cx ax =对任意0x 成立,所以椭圆E 的离心率13c e a ==.解法三:依题意,00,33x y G ⎛⎫ ⎪⎝⎭,因为IG x ⊥轴,设点I 坐标为0,3x t ⎛⎫ ⎪⎝⎭,可求直线1PF 方程为()00y y x c x c=++,则点I 到直线1PFt =,即()()()2222000003x y c t x c t y x c ⎛⎫⎛⎫+-+=++ ⎪⎪⎝⎭⎝⎭,化简得()22000002033x x y t t c x c y c ⎛⎫⎛⎫+++-+= ⎪ ⎪⎝⎭⎝⎭,①同理,由点I 到直线2PF 的距离等于t ,可得()22000002033x x y t t c x c y c ⎛⎫⎛⎫+----= ⎪ ⎪⎝⎭⎝⎭,②将式①-②,得00084233t cx y cx ⋅=⋅,则04y t =.将04y t =代入式①,得()2200001016233y x x c x c c ⎛⎫⎛⎫+++-+= ⎪ ⎪⎝⎭⎝⎭,化简得220022198x y c c+=,得229c a =,所以椭圆E 的离心率13c e a ==.(ⅱ)由26a =,得3a =,又13c a =,所以1c =,2228b a c =-=,所以椭圆E的方程为221 98x y+=.根楛椭圆对称性,不妨设点P在第一象限或y轴正半轴上,即0003,0x y≤<<≤又()11,0F-,()21,0F,所以直线1PF的方程为()11yy xx=++,设直线IG与1PF交于点D,因为03Dxx=,所以()()00331Dy xyx+=+,1FCD的面积1S与12PF F△的面积S之比为()()()()00200131123313118122y xxx xSS xy+⎛⎫+⨯⎪++⎝⎭==+⨯⨯,令()()()23181xf xx+=+(03x≤<),则()()()()231181x xf xx+-+'=,当[)0,1x∈,()0f x'<,当()1,3x∈,()0f x'>,所以函数()f x在[)0,1单调递减,在()1,3单调递增.又因为()12f=,()419f=,()132f=,所以()f x的值域是41,92⎡⎤⎢⎥⎣⎦,所以14192SS≤≤,所以11415SS S≤≤-,根据对称性,12PF F△被直线IG分成两个部分的图形面积之比的取值范围是45,54⎡⎤⎢⎥⎣⎦.【点睛】关键点点睛:第二问(ⅱ)的关键在于求得1FCD 的面积1S 与12PF F △的面积S 之比的表达式,由此即可顺利得解.19.记集合()()()()()()(){}000,R ,,,f x x D L l x kx b x x D f x l x x D f x l x ∈==+∈∀∈≤∃∈=且,集合()()()()()()(){}000,R ,,,f x x D T l x kx b x x D f x l x x D f x l x ∈==+∈∀∈≥∃∈=且,若()(),f x x D l x L ∈∈,则称直线()y l x =为函数()f x 在D 上的“最佳上界线”;若()(),f x x D l x T ∈∈,则称直线()y l x =为函数()f x 在D 上的“最佳下界线”.(1)已知函数()2f x x x =-+,()01l x kx =+.若()()0,R f x x l x L ∈∈,求k 的值;(2)已知()e 1xg x =+.(ⅰ)证明:直线()y l x =是曲线()y g x =的一条切线的充要条件是直线()y l x =是函数()g x 在R 上的“最佳下界线”;(ⅱ)若()()ln 1h x x =-,直接写出集合()()(),1,,R h x x g x x L T ∞∈+∈⋂中元素的个数(无需证明).【答案】(1)3k =或1-(2)(ⅰ)证明见解析;(ⅱ)2个【解析】【分析】(1)由题意可得R x ∀∈,21x x kx -+≤+,且0R x ∃∈,20001x x kx -+=+,再由△0=求解即可;(2)(ⅰ)结合“最佳下界线”及充要条件的定义证明即可;(ⅱ)由定义直接写出结果即可.【小问1详解】依题意,()()0,R f x x l x L ∈∈ ,R x ∴∀∈,21x x kx -+≤+,且0R x ∃∈,20001x x kx -+=+,令2()(1)1x x k x ϕ=-+--,2Δ(1)4k =--,则()0x ϕ≤,且0()0x ϕ=,∴Δ0,Δ0,≤⎧⎨≥⎩,∴Δ0=,即2(1)40k --=,12k -=或12k -=-,解得3k =或1-;【小问2详解】(ⅰ)先证必要性.若直线()y l x =是曲线()y g x =的切线,设切点为()00,e 1x x +,因为()e x g x '=,所以切线方程为()()000e 1e x x y x x -+=-,即()()000e 1e 1x xl x x x =+-+(*)一方面,()()00g x l x =,所以0x ∃∈R ,()()00g x l x =,另一方面,令()()()()000e e 1e x xx G x g x l x x x =-=---,则()00G x =,因为()0e e xx G x '=-,所以当0x x <时,()0G x '<,()G x 在()0,x ∞-单调递减,当0x x >时,()0G x '>,()G x 在()0,x ∞+单调递增,所以()()00G x G x ≥=,所以()()g x l x ≥.即x ∀∈R ,()()g x l x ≥,所以()(),R g x x l x T ∈∈,即()l x 是函数()g x 在R 上的“最佳下界线”.再证充分性.若()l x 是函数()g x 在R 上的“最佳下界线”,不妨设()l x kx b =+,由“最佳下界线”的定义,x ∀∈R ,()()g x l x ≥,且0x ∃∈R ,()()00g x l x =,令()()()e 1xH x g x l x kx b =-=+--,则()0H x ≥且()00H x =,所以()min 0H x =.因为()e xH x k '=-,①若0k ≤,则()0H x '≥,所以()H x 在R 上单调递增,所以10x x ∃<,使得()()100H x H x <=,故0k ≤不符合题意.②若0k >,令()0H x '=,得ln x k =,当(),ln x k ∞∈-时,()0H x '<,得()H x 在(),ln k ∞-单调递减,当()ln ,x k ∞∈+时,()0H x >,得()H x 在()ln ,k ∞+单调递增,所以,当且仅当ln x k =时,()H x 取得最小值()ln H k .又由()H x 在0x 处取得最小值,()min 0H x =,所以()0,ln 0,x lnk H k =⎧⎨=⎩即000e ,e 10,x x k kx b ⎧=⎪⎨+--=⎪⎩解得0e x k =,()001e 1x b x =-+,所以()()000e 1e 1x xl x x x =+-+,由(*)式知直线()y l x =是曲线()y g x =在点()00,e 1x x +处的切线.综上所述,直线()y l x =是曲线()y g x =的一条切线的充要条件是直线()y l x =是函数()g x 在R 上的“最佳下界线”.(ⅱ)集合()()(),1,,R h x x g x x L T ∞∈+∈⋂元素个数为2个.【点睛】方法点睛:新定义题型的特点是:通过给出一个新概念,或约定一种新运算,或给出几个新模型来创设全新的问题情景,要求考生在阅读理解的基础上,依据题目提供的信息,联系所学的知识和方法,实现信息的迁移,达到灵活解题的目的:遇到新定义问题,应耐心读题,分析新定义的特点,弄清新定义的性质,按新定义的要求,“照章办事”,逐条分析、验证、运算,使问题得以解决.。
1(在此卷上答题无效)2023~2024学年福州市高三年级2月份质量检测数学试题(完卷时间120分钟;满分150分)友情提示:请将所有答案填写到答题卡上!请不要错位、越界答题!一、单项选择题:本题共8小题,每小题5分,共40分。
在每小题给出的四个选项中,只有一项是符合题目要求的。
1.已知集合{}{}1,1,1A x x B =<=-,则A B =U A.(],1-∞ B.(),1-∞ C.{}1- D.{}1,1-2.已知点()2,2A 在抛物线2:2C x py =上,则C 的焦点到其准线的距离为A.12B.1C.2D.43.已知1e ,2e 是两个不共线的向量,若122λ+e e 与12μ+e e 是共线向量,则A.2λμ=- B.2λμ=- C.2λμ= D.2λμ=4.在ABC △中,2AB =,4AC =,BC =ABC △的面积为A.2B. C.4D.A. B. C. D.22227.甲、乙、丙三个地区分别有%x ,%y ,%z 的人患了流感,且,,x y z 构成以1为公差的等差数列.已知这三个地区的人口数的比为5:3:2,现从这三个地区中任意选取一人,在此人患了流感的条件下,此人来自甲地区的概率最大,则x 的可能取值为A.1.21B.1.34C.1.49D.1.518.已知函数()f x 及其导函数()'f x 的定义域均为R ,记()()='g x f x .若()2g x -的图象关于点()20,对称,且()()()22112---=-g x g x g x ,则下列结论一定成立的是2A.()()2f x f x =-B.()()2g x g x =+C.()20241==∑n g n D.()20241n f n ==∑二、多项选择题:本题共3小题,每小题6分,共18分。
在每小题给出的四个选项中,有多项符合题目要求.全部选对的得6分,部分选对的得部分分,有选错的得0分。
福州市高中毕业班数学质量检测答案Company Document number:WUUT-WUUY-WBBGB-BWYTT-1982GT参 考 答 案 一、选择题 1.C 2.A 3.C 4.B5.B 6.A 7.D 8.C 9.B 10.A11.B 12.A二、填空题13.2 14.938 15.(理)82;(文)31616.①②③三、解答题17.解:∵A、B、C是△ABC 的三个内角∴A+B+C=π,222CB A+-=π2分∴y=tg2cos 2cos 2sin 22C B C B CB A-++++ 4分2cos 2cos 2)2sin 2cos 2cos 2(sin 22tg CB CB C B A ++= 6 分2tg 2tg 2tg CBA++= 8分因此,任意交换两个角的位置,y 的值不变.10分18.解:(Ⅰ)设x1<x2则f(x1)-f(x2)=(12x +)122()12221-+--x x x aa)21)(22(2111x x x x a+--= 2分∵x1<x2,∴2122x x -<0又∵a<0,∴1-0221 x x a+∴当a<0时,f(x1)-f(x2)<0即f(x1)<f(x2)∴当a<0时,y=f(x)是R 上的增函数 4分(Ⅱ)设P (x ,y )是函数y =g (x )的图象上的一点,P(x ,y )关于直线x =1成对称的点为P ′(x′,y′)则⎩⎨⎧=-=∴⎪⎩⎪⎨⎧==+y y xx y y x x '2''12'6分由已知有y′=2x′-1∴y=22-x -1 即g(x)=22-x -1. 8分(Ⅲ)∵f(x)=0 ∴0122=-+x x a令t=2x,则t2-t+a=0∵a<0Δ=(-1)2-4a=1-4a>0∴t=2411224112,2411a a a x x --=-+=∴-±或10分 ∵当a<0时,1<a 41-∴2x=2411a --没有实数解. 由2x =2411a -+ 解得:x=log22411a -+ ∴当a<0时,f(x)=0的解为x=log2411a -+分 19.(Ⅰ)证:取AC中点D ,连ED ∵E是AB ′的中点∴ED∥2'21=C B ∵B′C⊥AC∴DE⊥AC 2分又∵△ABC是底角等于30°的等腰三角形∴BD⊥AC 3分BD∩DE=D ∴AC⊥面BDE∴AC⊥BE,即AC⊥BA′ 4分(Ⅱ)解:由(Ⅰ)小题知∠EDB是二面角B′—AC—B的一个平面角.∴∠EDB=45° ED=2BD=AD·tg30°=22333=⋅ 在△BDE 中,由余弦定理得:EB2=ED2+BD2-2ED·BDcos45° =2+4-222222=⋅⋅ ∴EB=2 6分∴△BDE是等腰直角三角形,DE⊥BEED是异面直线AC与BA ′的距离为2 8分(Ⅲ)连A′D∵EB=EA′=ED=2 ∴A′D⊥BD又AC⊥面BED A′D⊂面BED∴A′D⊥AC∴A′D ⊥面ABC 且A′D=2VB′—ABC=31S△ABC·A′D=D A AC BD ')(2131⋅⋅⋅ =338 11分 VB′—BEC=VC—BEB′=3421'21'==--ABC B ABB C V V 3 20.解:(Ⅰ)2000年底除了危旧住房和新型住房外的其它形式的住房面积为a-(a a 125)3141=+ 1分 每年拆除危旧住房面积为3031101a a =⋅ 依题意,得:a1=a a a a 3110131125%)201(4⋅-+++ a2=a a a a 30231125%)201(42-+++ a3=a a a a 30331125%)201(43-+++ 4分 一般地an =⎪⎪⎩⎪⎪⎨⎧≥++≤≤-+++)11(125%)201(4)101(3010125%)201(4n a a n a n a a n n 7分 (Ⅱ)由a a a n 4125%)201(4≥++ 9分 得a a n 12432.14≥⨯ 510151537.1413lg 2lg 23lg 43lg 3lg 43lg 2.1lg =-=∴≈-+-≥∴-≥取n n n 答:至少再经过5年才能使该地区的居民住房总面积翻两番.12分21.解:(Ⅰ)∵a1+1232232-=+++n n na a a ① 当n≥2时,a1+1132)1(2132-=-+++--n n a n a a a ② 由①-②得)1(]1[1222)1(22-=---=--a a a a na n n n n ∴an =(a2-1)n·a2n-2(n≥2)3分当n=1时,由已知得a1=a2-1∴an =(a2-1)n·a2n-2(n∈N)4分(Ⅱ)Sn=(a2-1)[1+2a2+3(a2)2+4(a2)3+…+(n-1)(a 2)n-2+n(a2)n-1]……①∴a2Sn=(a2-1)[a2+2(a2)2+3(a2)3+…+(n-1)(a2)n-1+n(a2)n]……②① -②得:(1-a2)Sn=(a2-1)[1+a2+(a2)2+…+(a2)n-1-n(a2)n]∵a>0且a≠1∴a2-1≠0 ∴Sn=-[1+a2+(a2)2+…+(a2)n-1-n(a2)n]=-n nna a a 22211+-- ⎪⎩⎪⎨⎧=-+-=-∞←∞→)1(1)1(0])1()1(1[lim )1(lim 222222 a a a a a n a S n n n n n n n 9分 (Ⅲ)(理)本题即证:22121+++++n a n a n a n n n ∵22121+-++++n a n a n a n n n 12分 )00(0)21()1()1)(21)(1()21()1()1(2)1()1(22222222224222222222222≠+--=-+-=-+-=---+-=---+-a a a a a a a a a a a a a a a a a a a n n n n n n 且∴22121+++++n a n a n a n n n 14分 22.解:(理)(Ⅰ)解:设椭圆C :)0(1)1(2222b a b y a x =+-∵2C=2,∴C=1∴右准线方程为x=a2+1 2分设M(x,y)、P(x0,y0)连接PB ,则|PA|2+|PB|2=|AB|2∴(|PA|2+|PB|2)-2|PA|·|PB|=4∴(2a2)-2·2|y0|=4y0=±(a2-1)4分由⎪⎩⎪⎨⎧-±==+=)1(1202a y y a x 消去a ,得y=±(x-2)∵0<|y0|<1,∴0<a2-1<1,1<a2<2∴2<x<3即M 点的轨迹方程是y=±(x-2)(2<x<3=7分(Ⅱ)解:设∠ABQ=α,α∈()2,4ππ,则 8分 |AB|=2,|PA|=|BQ|=2cosα|PQ|=|AB|-2|BQ|cosα=2-4cos2α 10分∴周长L=(2-4cos2α)+4cosα+2=-4(cosα-2)21+5 当cosα=21,即α=3π时,周长L 取最大值5. 12分 此时|BQ|=1,|AQ|=32a=|BQ|+|AQ|=1+3a2=(232)2312+=+b2=a2-1=23∴所求椭圆C 的方程为123232)1(22=++-y x 14分(文)(Ⅰ)解:设D 为AB 中点,连接DQ 、DP 、PB .当|PQ|=1时,△DPQ为正三角形,边长为1.从而 △DPA、△DQB也是边长为1的正三角形.∴|PA|=1,|PB|=3∴2a=|PA|+|PB|=1+3 3分 ∴a=232,2312+=+a又∵c=1∴b2=a2-c2=a2-1=23∴椭圆C 的方程为123232)1(22=++-y x 6分(Ⅱ)解:设椭圆C :)0(1)1(2222b a b y a x =+-∵2C=2,∴C=1∴右准线方程为x=a2+1 8分又设M (x,y),P(x0,y0)∵|PA|2+|PB|2=|AB|2∴(|PA|2+|PB|2)-2|PA|·|PB|=4 即(2a2)-2·2|y0|=4∴y0=±(a2-1) 11分由⎪⎩⎪⎨⎧-±==+=)1(1202a y y a x 消去a ,得y=±(x-2)∵0<|y0|<1 ∴0<a2-1<1,1<a2<2∴2<x<3即M 点的轨迹方程是y=±(x-2)(2<x<3)14分。
2021届福州市高中毕业班第三次质量检查数学(理科)详细解答一、选择题:本大题共12小题,每小题5分,共60分. 1. 已知纯虚数z 满足(1i)2i z a -=+,则实数a 等于A .2B .1C .1-D .2-【命题意图】本小题考查复数的概念与运算等基础知识;考查运算求解能力;考查函数与方程思想;考查数学运算等核心素养,体现基础性. 【答案】A .【解析】解法一:设i(,z b b =∈R 且0),b ≠则(1i)i i 2i.b b b a -=+=+ 因为a ∈R ,所以2,,b a b =⎧⎨=⎩所以2a =,故选A .解法二:2i (2i)(1i)22i 1i 222a a a a z +++-+===+-. 因为z 为纯虚数,所以20,20,a a -=⎧⎨+≠⎩解得2a =,故选A.2. 已知集合{}(){}2220,log 2A x x x B x y x =+-==-<,则()AB =RA .∅B .(]2,2-C .()1,2D .()2,1-【命题意图】本小题考查解一元二次不等式、函数的定义域,集合的交集、补集运算等基础知识;考查运算求解能力;考查数学运算核心素养,体现基础性. 【答案】D .【解答】依题意,{}{}21,2A x x B x x =-=<<>,所以B =R{}2x x ≤,所以()AB =R()2,1-.3. 执行右面的程序框图,则输出的m =A .1B .2C .3D .4【命题意图】本小题考查程序框图等基础知识;考查推理论证能力;考查逻辑推理核心素养,体现基础性. 【答案】C .【解答】该框图的功能为求小于12的正整数中3的倍数的个数,故输出的m 值应为3,故选C . 4.5. 函数()2e 2x f x x x =--的图象大致为ABCD【命题意图】本小题考查函数的图象与性质等基础知识;考查运算求解能力;考查数形结合思想,考查直观想象、数学运算等核心素养,体现基础性. 【答案】B .【解答】解法一:因为()()e 22,e 2x x f x x f x '''=--=-,令()e 20x f x ''=-=,得ln2x =,当ln 2x <时()0f x ''<,()f x '为减函数;当ln 2x >时,()0f x ''>,()f x '为增函数,而()ln 222ln 222ln 20f '=--=-<,所以原函数存在两个极值点,故淘汰选项C 和D .将1x =代入原函数,求得()1e 120f =--<,淘汰选项A ,故选B .解法二:()1e 210f =--<,淘汰选项A ,D ;当x →-∞时,()e x f x =-()2x x +→-∞,淘汰选项C .故选B .6. 甲、乙、丙、丁四名同学在某次军训射击测试中,各射击10次.四人测试成绩对应的条形图如下:以下关于四名同学射击成绩的数字特征判断不正确...的是 A .平均数相同B .中位数相同C .众数不完全相同D .丁的方差最大【命题意图】本小题考查统计图表、数字特征的概念等基础知识;考查运算求解能力;考查数形结合思想、统计与概率思想;考查直观想象、数据处理、数学运算等核心素养,体现基础性、应用性. 【答案】D .【解析】由图的对称性可知,平均数都为5;由图易知,四组数据的众数不完全相同,中位数相同;记甲、乙、丙、丁图所对应的方差分别为22221234,,,s s s s ,则()()2221450.5650.51s =-⨯+-⨯=,()()()22222450.3550.4650.30.6s =-⨯+-⨯+-⨯=,()()()()()2222223350.3450.1550.2650.1750.3 2.6s =-⨯+-⨯+-⨯+-⨯+-⨯=, ()()()()()2222224250.1450.3550.2650.3850.1 2.4s =-⨯+-⨯+-⨯+-⨯+-⨯=,所以丙的方差最大.故选D . 7. 已知角θ的终边在直线3y x =-上,则2sin 21cos θθ=+ A .611-B .311-C .311D .611【命题意图】本小题考查三角函数的定义、三角恒等变换等基础知识;考查运算求解能力、推理论证能力;考查数形结合思想;考查数学运算、直观想象等核心素养,体现基础性. 【答案】A .【解析】解法一:依题意,tan 3θ=-,所以原式2222sin cos 2tan 6sin 2cos tan 211θθθθθθ===-++,故选A .解法二:不妨在直线3y x =-上取一点()1,3P -,则r,所以cosθsin θ=所以6sin 22sin cos 10θθθ==-,原式6610111110-==-+,故选A .8. 数独是源自18世纪瑞士的一种数学游戏.如图是数独的一个简化版,由3行3列9个单元格构成.玩该游戏时,需要将数字1,2,3(各3个)全部填入单元格,每个单元格填一个数字,要求每一行、每一列均有1,2,3这三个数字,则不同的填法有 A .12种 B .24种 C .72种D .216种【命题意图】本小题考查计数原理等基础知识;考查运算求解能力、应用意识;考查数学抽象、数学建模、逻辑推理等核心素养,体现综合性和应用性. 【答案】A .【解答】先填第一行,有336A =种不同填法,再填第二行第一列,有2种不同填法,当该单元格填好后,其它单元格唯一确定.根据分步乘法计数原理,共有6212⨯=种不同的填法.故选A .9. 已知函数()()sin 06f x x ωωπ⎛⎫=+ ⎪⎝⎭>图象上相邻两条对称轴的距离为2π,把()f x 图象上各点的横坐标伸长到原来的2倍,纵坐标不变,再把得到的图象向右平移35π个单位长度,得到函数()g x 的图象,则 A .()cos 4g x x =- B .()cos 4g x x =C .()cos g x x =-D .()cos g x x =【命题意图】本小题考查三角函数图象的变换、诱导公式等基础知识;考查运算求解能力;考查数形结合思想;考查数学运算、直观想象等核心素养,体现基础性. 【答案】D . 【解析】依题意,2T =2π,所以T =π,所以2ωπ=π,解得ω=2,所以()f x =sin 26x π⎛⎫+ ⎪⎝⎭.把()f x 图象上各点的横坐标伸长到原来的2倍,纵坐标不变,得到曲线sin 6y x π⎛⎫=+ ⎪⎝⎭,再把曲线sin 6y x π⎛⎫=+ ⎪⎝⎭向右平移35π个单位长度,得到曲线sin 63y x π5π⎛⎫=+- ⎪⎝⎭,即cos y x =,故()cos g x x =,故选D . 10. 已知椭圆2222:1x y C a b+=(0a b >>)的焦距为2,右顶点为A .过原点与x 轴不重合的直线交C 于,M N 两点,线段AM 的中点为B ,若直线BN 经过C 的右焦点,则C 的方程为A .22143x y +=B .22165x y +=C .22198x y +=D .2213632x y +=【命题意图】本小题考查直线与椭圆的位置关系等基础知识;考查运算求解能力、推理论证能力;考查数形结合思想、函数与方程思想等;考查数学运算、直观想象等核心素养,体现基础性. 【答案】C .【解析】解法一:设()00,M x y ,则()00,N x y --,因为(),0A a 且线段AM 的中点为B ,所以00,22a x y B +⎛⎫⎪⎝⎭,由,,B F N 三点共线得FN FB ∥,依题意,()1,0F ,故FN =()001,,x y ---001,22a x y FB +⎛⎫=-⎪⎝⎭即()000011022y a x x y +⎛⎫-++-= ⎪⎝⎭,又00y ≠,解得3=a ,所以222318b =-=,所以椭圆C 的标准方程为22198x y +=,故选C .解法二:设()00,M x y ,则()00,N x y --,依题意,(),0A a ,AO NB 和是AMN △的中线,所以()1,0F 为AMN △的重心,故0013x x a-+=,解得3a =,所以222318b =-=,所以椭圆C 的标准方程为22198x y +=.故选C .11. 已知函数()1ln f x x x x=-+,给出下列四个结论: ①曲线()y f x =在1x =处的切线方程为10x y +-=; ②()f x 恰有2个零点;③()f x 既有最大值,又有最小值;④若120x x >且()()120f x f x +=,则121x x =. 其中所有正确结论的序号是 A .①②③B .①②④C .①②D .③④【命题意图】本小题考查函数的图象性质、导数的应用等基础知识;考查运算求解能力、推理论证能力;考查数形结合思想、函数与方程思想等;考查数学运算、直观想象等核心素养,体现基础性、综合性. 【答案】B .【解答】依题意,()f x 的定义域为()(),00,-∞+∞.当0x >时,()2221111x x f x x x x-+-'=--=,所以()11f '=-,可知曲线在点()1,0处的切线方程为()01y x -=--,即10x y +-=,所以①正确;因为0x >时,()2213240x f x x ⎛⎫---⎪⎝⎭'=<,所以()f x 区间()0,+∞上单调递减.同理可求()f x 在区间(),0-∞上单调递减.所以③错误;又()()10,10f f -==,所以②正确; 对于④,若120x x >0,>,由()()120f x f x +=得()()122221ln f x f x x x x ⎛⎫=-=--+=⎪⎝⎭21lnx +2221111f x x x ⎛⎫-= ⎪⎝⎭,即()121f x f x ⎛⎫= ⎪⎝⎭.因为()f x 在()0,+∞上为减函数,所以121x x =,即121x x =.同理可证当120,0x x <<时,命题也成立.故④正确. 综上,故选B .12. 三棱锥P ABC -中,顶点P 在底面ABC 的投影为ABC △的内心,三个侧面的面积分别为12,16,20,且底面面积为24,则三棱锥P ABC -的内切球的表面积为 A .43π B .12π C .163πD .16π【命题意图】本小题考查空间点、线、面位置关系,空间几何体的侧面积、体积等基本知识;考查空间想象能力、运算求解能力、论证推理能力;考查化归与转化思想;考查直观想象、数学运算等核心素养,体现基础性、创新性. 【答案】C .【解答】解法一:不妨设12,16,20,PBC PAC PAB S S S ===△△△设P 在底面ABC 的投影为H ,分别作HD BC ⊥于点D ,HE AB ⊥于点E ,HF AC ⊥于点F ,则,PD BC ⊥,PE AB ⊥PF AC ⊥.依题意,H 为ABC △的内心,则Rt Rt Rt PDH PFH PEH △≌△≌△,故PD PF PE ==,又12PBC S BC PD =⋅△,12PAC S AC PF =⋅△,12PAB S AB PE =⋅△, 所以::::12:16:203:4:5PBC PAC PAB S S S BC AC AB ===△△△,所以90ACB ∠=︒.令3,4,5BC x AC x AB x ===. 所以11342422ABC S BC AC x x =⋅=⋅⋅=△,解得2x =,所以6,8,10BC AC AB ===. 设ABC △内切圆半径为r ,则()12ABC BC AC AB r S ++=△,即()16810242r ⨯++=,解得2r =,故2HD =.由112,62PBC S BC PD BC =⋅==△,得4PD =,所以2223PH PD HD =-=,所以11242316333P ABC ABC V S PH -=⋅=⨯⨯=△,设三棱锥P ABC -的内切球的半径为R ,则()13P ABC PBC PAC PAB ABC V S S S S R -=+++△△△△,即()1163121620243R =⨯+++,解得23R =,所以三棱锥P ABC -的内切球的表面积为21643R ππ=,故选C . 解法二:不妨设12,16,20,PBC PAC PAB S S S ===△△△设P 在底面ABC 的投影为H ,分别作HD BC ⊥于点D ,HE AB ⊥于点E ,HF AC ⊥于点F ,则,PD BC ⊥,PE AB ⊥PF AC ⊥.依题意,H 为ABC △的内心,则Rt Rt Rt PEH PFH PDH △≌△≌△,故PD PF PE ==,且PEH PFH PDH ∠=∠=∠,记为θ. 所以cos HE HF HDPE PF PDθ===,故cos HAC HBC HAB PAB PAC PBC S S S S S S θ===△△△△△△,所以1cos 2BC PABPAC PBC S S S S θ==++△A △△△,所以π3θ=.又12PBC S BC PD =⋅△,12PAC S AC PF =⋅△, 12PAB S AB PE =⋅△, 所以::::12:16:203:4:5PBC PAC PAB S S S BC AC AB ===△△△,所以90ACB ∠=︒. 令3,4,5BC x AC x AB x ===. 所以11342422ABC S BC AC x x =⋅=⋅⋅=△,解得2x =,所以6,8,10BC AC AB ===. 设ABC △内切圆半径为r ,由直角三角形内切圆半径公式得681022r +-==. 由题意知三棱锥内切球的球心在PH 上,设为点O .由条件知点O 也在PDH ∠的角平分线上,所以内切球半径tan30R r =︒=所以三棱锥P ABC -的内切球的表面积为21643R ππ=,故选C . 二、填空题:本大题共4小题,每小题5分,共20分.13. 已知向量()1,2AB =,()2,5CB =,(),1t MN =.若AC MN ∥,则实数t = .【命题意图】本小题考查平面向量坐标运算等基础知识;考查运算求解能力;考查数形结合思想、函数与方程思想等;考查数学运算、直观想象等核心素养,体现基础性.【答案】13.【解析】因为()()()1,22,51,3AC AB CB =-=---=,又因为(),1t MN =,AC MN ∥, 所以()113t -⨯=-,解得13t =. 14. 正方体1111ABCD A B C D -中,P 为1BC 中点,Q 为1A D 中点,则异面直线DP 与1C Q 所成角的余弦值为 .【命题意图】本小题考查空间直线与直线的位置关系等基本知识;考查空间想象能力、运算求解能力、推理论证能力;考查化归与转化思想;考查直观想象、数学运算等核心素养,体现基础性.【答案】23.【解答】解法一:连结11,CB QB ,因为四边形11BCC B 为正方形,P 为1BC 中点,所以1112B P BC =.因为11//A B CD ,所以四边形11CDA B 为平行四边形,所以11//B C A D ,又Q 为1A D 中点,所以1//B P DQ ,所以四边形1DPB Q 为平行四边形,所以1B Q DP ∥,所以11B QC ∠为异面直线DP 与1C Q 所成角或其补角.设正方体的棱长为2,在1Rt BAQ △中,221111246B Q AQ A B =+=+=; 同理可求16C Q =.在11B C Q △中,222111111112cos 23266B Q C Q B C C QB B Q C Q +-∠===⋅⨯⨯,故异面直线DP 与1C Q 所成角的余弦值为23.解法二:如图,以D 为原点,分别以1,,DA DC DD 的方向为,,x y z 轴的正方向,建立空间直角坐标系D xyz -.设正方体的棱长为2,则各点的坐标为()()0,0,0,1,2,1,D P ()10,2,2,C ()1,0,1Q ,所以()()11,2,1,1,2,1DP C Q ==--, 所以1cos ,DP C Q =11DP C Q DP C Q⋅=66=⨯23-.所以异面直线DP 与1C Q 所成角的余弦值为23.解法三:设正方体的棱长为2,1,,,DA DC DD ===a b c 则()111222DP =++=++b a c a b c ,()1111222C Q =-+-=--b a c a b c , 由1,,DA DC DD 三条直线两两垂直得0⋅=⋅=⋅=a b b c a c ,所以2222222211111112224224444DP C Q ⎛⎫⎛⎫⋅=-+=--=⨯--⨯=- ⎪ ⎪⎝⎭⎝⎭a b c a b c ,222222111116,64444DP C Q =++==++=a b c a b c , 所以1cos ,DP C Q =11DP C Q DP C Q⋅=66=⨯23-.所以异面直线DP 与1C Q 所成角的余弦值为23. 15. 在ABC △中,内角,,A B C 的对边分别为,,a b c ,若22sin cos 1A B +=,则cb a-的取值范围为 .【命题意图】本小题考查解三角形等基础知识;考查运算求解能力;考查数形结合思想、函数与方程思想、化归与转化思想等;考查数学运算、直观想象等核心素养,体现基础性. 【答案】()2,3.【解析】在ABC △中,因为22sin cos 1A B +=,所以cos cos2B A =,所以2B A =. 由正弦定理及题设得()sin sin sin cos2cos sin 2sin sin sin sin sin 2sin A B c CA A A A b aB A B A A A++====----()22sin 2cos 12sin cos 2sin cos sin A A A AA A A-+=-24cos 12cos 12cos 1A A A -=+-,由02π,0π3πB A C A =⎧⎨=-⎩<<<<得π03A <<,故1cos 12A <<,所以cb a-的取值范围为()2,3. 16. 已知梯形ABCD 满足,45AB CD BAD ∠=︒∥,以,A D 为焦点的双曲线Γ经过,B C 两点.若7CD AB =,则Γ的离心率为 .【命题意图】本小题考查直线与双曲线的位置关系等基础知识;考查运算求解能力、推理论证能力;考查数形结合思想、函数与方程思想;考查数学运算、直观想象等核心素养,体现基础性、综合性.【解答】解法一:如图所示,以AD 中点O 为原点,以AD 为x 轴,建立直角坐标系. 设点C 关于点O 对称的点为C ',由对称性知,B ,A ,C '三点共线.设Γ的方程为)00(12222>>=-b a b y a x ,,)0,(c A -,11(,)B x y ,22(,)C x y ',则直线BC '方程为c x y +=,由2222,1y x c x y ab =+⎧⎪⎨-=⎪⎩得22224()20b a y b cy b --+=, 所以()4242240b c b b a ∆=-->,24121222222,b c b y y y y b a b a +==--,由7CD AB =,所以217y y =, 因为12,y y 异号,所以217y y =-,由21212227,2,y y b c y y b a =-⎧⎪⎨+=⎪-⎩,解得⎪⎪⎩⎪⎪⎨⎧-=--=)(37)(322222221a b c b y a b cb y , 代入22421ab b y y -=,得)(97222a bc -=-, 因为222a c b -=,所以2289c a =, 所以Γ的离心率324c e a ==. 解法二:如图所示,以AD 中点O 为原点,以AD 为x 轴,建立直角坐标系.设Γ的方程为)00(12222>>=-b a by a x ,,)0,(c A -.依题意,设(),B m m c -,则()7,7C c m m +,()()222222221,(1)7491,(2)m c m a bc m ma b ⎧--=⎪⎪⎨+⎪-=⎪⎩由()()1492⨯-得()2223377c a b m cc-==, 将237b m c=代入(1)得422491780a a c c -+=,解得2298a c =或22a c =(舍去),所以Γ的离心率324c e a ==. 解法三:如图,连接,AC BD .设该双曲线的焦距2AD c =,实轴长为2a ,则BD -2AB AC CD a =-=.设AB m =,则7CD m =,2,27BD a m AC a m =+=+.依题意,45,135BAD ADC ∠=︒∠=︒, 在ABD △中,由余弦定理及题设得()2222422a m m c mc +=+-,在ACD △中,由余弦定理及题设得()22227494142a m m c mc +=++,A DCB))22,c a m c -=+))227c a mc -=-,两式相除得18c =,故Γ的离心率c e a =. 三、解答题:本大题共6小题,共70分. 17. (本小题满分12分)已知数列{}n a 和{}n b 的前n 项和分别为n S ,n T ,12a =,11b =,且112n n a a T +=+. (1)若数列{}n a 为等差数列,求n S ;(2)若112n n b b S +=+,证明:数列{}n n a b +和{}n n a b -均为等比数列.【命题意图】本小题考查等差数列、等比数列等基础知识;考查运算求解能力、推理论证能力;考查化归转化思想;考查数学运算、逻辑推理等学科素养;体现基础性.满分12分.【解答】(1)由112n n a a T +=+,得2112a a b =+,又12a =,11b =,解得24a =. ································································· 1分 因为数列{}n a 为等差数列,所以该数列的公差为21a a -=2, ························ 2分 所以()21222n n n S n n n -=+⋅=+.··························································· 4分 (2)当2n ≥时,112n n a a T -=+,因为1n n n T T b --=,所以12n n n a a b +-=,即12n n n a a b +=+, ···························· 5分 同理可得:12n n n b b a +=+. ···································································· 6分 则113()n n n n a b a b +++=+,所以113n n n na b a b +++=+(2n ≥), ································· 7分又21121124,25a a b b b a =+==+=, 所以22114533a b a b ++==+, 所以113n n n na b a b +++=+(*n ∈N ), ································································ 8分所以数列{}n n a b +是以3为首项,3为公比的等比数列. ································ 9分 因为11()n n n n a b a b ++-=--,所以111n n n na b a b ++-=--(2n ≥), ·························· 10分又221145121a b a b --==---,所以111n n n na b a b ++-=--(*n ∈N ), ······························ 11分 所以数列{}n n a b -是以1-为首项,1-为公比的等比数列. ························· 12分 18. (本小题满分12分)如图,在多面体PABCD 中,平面ABCD ⊥平面PAD ,AD BC ∥,90BAD ∠=︒,120PAD ∠=︒,1BC =,2AB AD PA ===.(1)求平面PBC 与平面PAD 所成二面角的正弦值; (2)若E 是棱PB 的中点,求证:对于棱CD 上任意一点F ,EF 与PD 都不平行.【命题意图】本小题考查直线与平面垂直的判定与性质,直线与平面平行、平面与平面平行的判定与性质,二面角等基础知识;考查空间想象能力、推理论证能力、运算求解能力;考查化归与转化思想、函数与方程思想;考查直观想象、逻辑推理等核心素养,体现基础性、综合性.满分12分.【解析】解法一:(1)因为AB AD ⊥,平面ABCD ⊥平面PAD , 平面ABCD 平面PAD AD =,AB ⊂平面ABCD , 所以AB ⊥平面PAD . ·········································· 1分 作AH AD ⊥交PD 于H ,则,,AB AD AH 三条直线两两垂直.以A 为坐标原点O ,分别以AH AD AB ,,所在直线为,,x y z 轴,建立空间直角坐标系,如图所示. ················ 2分 因为120PAD ∠=︒,1BC =,2AB AD PA ===. 所以()()()())0,0,0,0,0,2,0,1,2,0,2,0,1,0A B C D P-, ····························· 3分 设平面PBC 的法向量为(),,x y z =n ,因为()()0,1,0,3,1,2BC BP ==--,所以0,0,BC BP ⎧⋅=⎪⎨⋅=⎪⎩n n 所以0,20,y y z =⎧⎪--=令2x =,所以(=n , ·············· 4分由z 轴⊥平面PAD 知()0,0,1=m 为平面PAD 的一个法向量, ··························· 5分所以cos ,⋅<>===⋅n m n m n m, ················································· 6分P ADCBP所以PBC 与平面PAD. ··································· 7分 (2)因为E 是棱PB 的中点,由(1)可得1,12E ⎫-⎪⎪⎝⎭.假设棱CD 上存在点F ,使得EF PD , ·················································· 8分 设DF DC λ=,01λ≤≤,所以()55,10,1,2,1222EF ED DF λλλ⎛⎫⎛⎫=+=-+-=--+ ⎪ ⎪ ⎪ ⎪⎝⎭⎝⎭, ·········· 9分 因为EF PD,所以()EF tPD t ==, ·· 10分所以53,2120,t λλ⎧=⎪⎪⎪⎪-=⎨⎪⎪-+=⎪⎪⎩这个方程组无解, ···············11分 所以假设不成立,所以对于棱CD 上任意一点F ,EF 与PD 都不平行. ·········· 12分 解法二:(1)如图,在平面PAD 内,过点P 作DA 的垂线,垂足为M ;在平面ABCD 内,过M 作AD 的垂线,交CB 的延长线于点N .连接PN .因为MN PM M =,所以AD ⊥平面PMN . ············· 1分 因为AD BC ∥,BC ⊂平面PBC ,AD ⊄平面PBC , 所以AD ∥平面PBC , ··········································· 2分 设平面PBC平面PAD l =,则AD l ∥,故l ⊥平面PMN . ········································································································ 3分 所以NPM ∠为平面PBC 与平面PAD 所成二面角的平面角. ························· 4分 因为120PAD ∠=︒,2AB AD PA ===,所以60MAP ∠=︒,在Rt PAM △中,2sin 60PM =︒ ····················································· 5分 又2MN AB ==,所以在Rt PMN △中,PN = ················ 6分所以sin MN MPN PN =∠ 所以PBC 与平面PAD. ··································· 7分PAB CDPNM(2)假设棱CD 上存在点F ,使得EF PD ,显然F 与点D 不同, ··································································· 8分 所以,,,P E F D 四点共面,记该平面为α,所以P α∈,PE α⊂,FD α⊂, ···················································· 9分 又B PE ∈,C FD ∈,所以B α∈,C α∈,所以α就是点,,B C D 确定的平面, ························································ 10分 这与P ABCD -为四棱锥相矛盾,所以假设不成立,所以对于棱CD 上任意一点F ,EF 与PD 都不平行. ·································· 12分 解法三:(1)同解法一. ······································································· 7分 (2)假设棱CD 上存在点F ,使得EF PD . ·········································· 8分 连接BD ,取BD 的中点M ,在△BPD 中,因为,E M 分别为,BP BD 的中点, 所以EMPD . ···················································· 9分 因为过直线外一点有且只有一条直线和已知直线平行,所以EM 与EF 重合. ······················································································· 10分 又点F 在线段CD 上,所以F BD CD =,又BD CD D =,所以F 是BD 与CD 的交点D ,即EF 就是ED , ······································ 11分 而ED 与PD 相交,所以与EFPD 相矛盾,所以假设不成立,所以对于棱CD 上任意一点F ,EF 与PD 都不平行. ································ 12分 19. (本小题满分12分)已知抛物线2:4C y x =,直线:2l x my =+(0m >)与C 交于,A B 两点,M 为AB 的中点,O 为坐标原点.(1)求直线OM 斜率的最大值;(2)若点P 在直线2x =-上,且PAB △为等边三角形,求点P 的坐标.【命题意图】本题考查抛物线方程、直线与抛物线的位置关系等基础知识;考查运算求解能力;考查数形结合思想、函数与方程思想;考查直观想象、数学运算等核心素养,体现基础性、综合性.满分12分.【解析】解法一:(1)设1122(,),(,)A x y B x y ,由22,4x my y x =+⎧⎨=⎩,消去x 得,2480y my --=, ··········································· 1分AB CP CEFABCPCEAM216320,m ∆=+>且12124,8y y m y y +==-. ················································ 2分所以21212()44 4.x x m y y m +=++=+ 因为M 为AB 的中点, 所以M 的坐标为1212(,)22x x y y ++,即2(22,2)m m +, ···································· 3分 又因为0m >,所以2221112212OM m m k m m m m ====+++, ·················· 5分 (当且仅当1m m=,即1m =等号成立.) 所以OM 的斜率的最大值为12. ······························································ 6分(2)由(1)知,12|AB y y -== ····································································· 8分 由PM AB ⊥得22||22(2)|2(PM m m +--=+, ·············· 9分 因为PAB △为等边三角形,所以||||PM AB , ··································· 10分所以22(m +=21m =,解得1,m =±又0m >,所以1m =, ······································································· 11分 则(4,2)M ,直线MP 的方程为2(4)y x -=--,即6y x =-+, 所以2x =-时,8y =,所以所求的点P 的坐标为(2,8)-. ························································· 12分 解法二:(1)设112200(,),(,),(,)A x y B x y M x y , 因为M 为AB 的中点,且直线:2(0)l x my m =+>,所以0122,y y y =+1212,x x m y y -=- ································································ 1分 由2112224,4,y x y x ⎧=⎪⎨=⎪⎩得22121244,y y x x -=-所以()1212124,x x y y y y -+=-所以024,y m =即02y m =. ······································· 2分 所以200222,x my m =+=+即2(22,2)M m m +, ·········································· 3分 又因为0m >,所以2221112212OM m m k m m m m ====+++, ················· 5分 (当且仅当1m m=,即1m =等号成立.) 所以OM 的斜率的最大值为12. ······························································ 6分(2)由22,4x my y x=+⎧⎨=⎩,消去x 得2480y my --=,所以216320,m ∆=+>且12124,8y y m y y +==-. ·········································· 7分AB =====····································································· 8分 由(1)知,AB 的中点M 的坐标为2(22,2)m m +,所以线段AB 的垂直平分线方程为:()2222y m m x m -=---.令2x =-,得线段AB 的垂直平分线与直线2x =-交点坐标为()32,26,P m m -+所以22(m M P + ·························· 9分。
福州市高中毕业班质量检查数学理科试卷(满分150分,考试时间1)参考公式:样本数据x 1,x 2,… ,x n 的标准差锥体体积公式V=31Sh 其中x 为样本平均数 其中S 为底面面积,h 为高柱体体积公式 球的表面积、体积公式V=Sh24S R =π,343V R =π 其中S 为底面面积,h 为高其中R 为球的半径一.选择题(本大题共10小题,每小题5分,共50分. 在每小题给出的四个选项中,只有一项是是正确的, 将正确答案填写在答题卷相应位置.) 1.如果复数z =(a 2-3a +2)+(a -1)i 为纯虚数,则实数a 的值 ( ).A.等于1或2B.等于1C.等于2D.不存在 2.曲线f (x )=x 3+x -2在0P 点处的切线平行于直线y =4x -1,则P 0点的坐标为( ) A.(1,0)或(-1,-4) B.(0,1) C.(1,0) D.(-1,-4)3. 已知数列{}n a 为等差数列,且1713212,tan()a a a a a π++=+则的值为( )B. C. D.4. 给定下列四个命题:①分别与两条异面直线都相交的两条直线一定是异面直线; ②若一个平面经过另一个平面的垂线,那么这两个平面相互垂直; ③垂直于同一直线的两条直线相互平行;④若两个平面垂直,那么一个平面内与它们的交线不垂直的直线与另一个平面也不垂直. 其中,为真命题的是( )A. ①和②B. ②和③C. ③和④D. ②和④ 5.某学校开展研究性学习活动,某同学获得一组实验数据如下表:俯视图左视图主视图对于表中数据,现给出以下拟合曲线,其中拟合程度最好的是( )A.y =2x -2B.y =(12)xC.y =log 2xD.y =12(x 2-1)6.设22)1(,3005,y x x y x y x y x ++⎪⎩⎪⎨⎧≤≥+≥+-则满足约束条件的最大值为( )A. 80B. C.25 D.1727. 已知12,a a 均为单位向量,那么131,22a ⎛⎫= ⎪⎪⎝⎭是()123,1a a +=的( )A.充分不必要条件 B.必要不充分条件 C.充分必要条件 D.既不充分又不必要条件 8.某程序框图如图所示,则该程序运行后输出的S 的值为( ) A.1 B.12C.14D.189.已知F 1、F 2为椭圆2212516x y +=的左、右焦点,若M 为椭圆上 一点,且△MF 1F 2的内切圆的周长等于3π,则满足条件的点M 有( )个.A.0B.1C.2D.410.已知函数f (x +1)是定义在R 上的奇函数,若对于任意给定的不等实数x 1、x 2,不等式1212()[()()]0x x f x f x --<恒成立,则不等式f (1-x )<0的解集为( ).A.(1,+∞)B.(0,+∞)C.(-∞,0)D.(-∞,1)二.填空题(本大题共5小题,每小题4分,共将正确答案填写在答题卷相应位置.)11.二项式10112x ⎛⎫- ⎪⎝⎭的展开式中第六项的系数等于__________(用数字作答)12. 在等比数列{}n a 中,首项=1a 32,()44112a x dx =+⎰,则公比q 为 .13.四棱锥P ABCD -的顶点P 在底面ABCD 中的投影恰好是A ,其三视图如右图所示,根据图中的信息,在四棱锥P ABCD -的任两个顶点的连线中,互相垂直的异面直线对数为 .(第8题)D ABFC14.在区间[π,π]-内随机取两个数分别记为,a b ,则使得函数222()2f x x ax b π=+-+有零点的概率为 .15.将杨辉三角中的奇数换成1,偶数换成0,得到如图1所示的0—1三角数表.从上往下数,第1次全行的数都为1的是第1行,第2次全行的数都为1的是第3行,…,第n 次全行的数都为1的是第 行. 第1行 1 1 第2行 1 0 1 第3行 1 1 1 1 第4行 1 0 0 0 1 第5行 1 1 0 0 1 1 …… ……………………………………三、解答题(本大题共6小题,共80分,解答应写在答题卷相应位置,要写出文字说明、证明过程或演算过程.)16.(本小题满分13分) 已知函数1()cos 2f x x x ππ=+, x R ∈. (Ⅰ)求函数()f x 的最大值和最小值;(Ⅱ)设函数()f x 在[1,1]-上的图象与x 轴的交点从左到右分别为M 、N ,图象的最高点为P,求PM 与PN 的夹角的余弦. 17.(本小题满分13分)“石头、剪刀、布”是一种广泛流传于我国民间的古老游戏,其规则是:用三种不同的手势分别表示石头、剪刀、布;两个玩家同时出示各自手势1次记为1次游戏,“石头”胜“剪刀”,“剪刀”胜“布”,“布”胜“石头”;双方出示的手势相同时,不分胜负.现假设玩家甲、乙双方在游戏时出示三种手势是等可能的. (Ⅰ)求出在1次游戏中玩家甲胜玩家乙的概率;(Ⅱ)若玩家甲、乙双方共进行了3次游戏,其中玩家甲胜玩家乙的次数记作随机变量X ,求X 的分布列及其期望.18.(本小题满分13分)如图,矩形ABCD 和梯形BEFC 所在平面互相垂直, BE//CF ,BC ⊥CF ,AD =EF =2,BE =3,CF =4.(Ⅰ)求证:EF ⊥平面DCE ;(Ⅱ)当AB 的长为何值时,二面角A-EF-C 的大小为60°. 19.(本小题满分13分)已知点M(k,l )、P (m,n ),(klmn ≠0)是曲线C 上的两点,点M 、N 关于x 轴对称,直线MP 、NP 分别交x 轴于点E(x E ,0)和点F (x F ,0),(Ⅰ)用k 、l 、m 、n 分别表示E x 和F x ;(Ⅱ)当曲线C 的方程分别为:222(0)x y R R +=> 、22221(0)x y a b a b+=>>时,探究E F x x ⋅的值是否与点M 、N 、P 的位置相关;(Ⅲ)类比(Ⅱ)的探究过程,当曲线C 的方程为22(0)y px p =>时,探究E x 与F x 经加、减、乘、除的某一种运算后为定值的一个正确结论.(只要求写出你的探究结论,无须证明).本小题满分14分)设函数f (x )=e x +sinx,g (x )=ax,F (x )=f (x )-g (x ). (Ⅰ)若x =0是F (x )的极值点,求a 的值;(Ⅱ)当 a =1时,设P (x 1,f (x 1)), Q (x 2, g (x 2))(x 1>0,x 2>0), 且PQ //x 轴,求P 、Q 两点间的最短距离; (Ⅲ):若x ≥0时,函数y =F (x )的图象恒在y =F (-x )的图象上方,求实数a 的取值范围. 21.(本小题满分14分)本题共有(1)、(2)、(3)三个选答题,每题7分,请考生任选2题作答,满分14分.如果多做,则以所做的前2题计分.作答时,先用2B 铅笔在答题卡上把所选题目对应的题号涂黑,并将所选题号填入括号中. (1)(本小题满分7分)选修4-2:矩阵与变换已知二阶矩阵M 有特征值3λ=及对应的一个特征向量111⎡⎤=⎢⎥⎣⎦e ,并且矩阵M 对应的变换将点(1,2)-变换成(9,15). 求矩阵M .(2)(本小题满分7分)选修4-4:坐标系与参数方程 在直角坐标系xOy 中,已知曲线C 的参数方程是22sin ,2cos x y αα=+⎧⎨=⎩(α是参数).现以原点O 为极点,x 轴的正半轴为极轴,建立极坐标系,写出曲线C 的极坐标方程. (3)(本小题满分7分)选修4-5:不等式选讲 解不等式2142x x +-->.福州市高中毕业班质量检查数学理科试卷参考答案和评分标准一.选择题 1.C 2.A 3.B 4.D 5.D 6.A 7.B 8.C 9.C 10.C 二.填空题 11.638- 12.3 13.6 14.1-4π 15.21n-三.解答题16.解:(Ⅰ)∵1()cos 22f x x x ππ=+=sin()6x ππ+.-----------------------------2分∵x R ∈ ∴1sin()16x ππ-≤+≤,∴函数()f x 的最大值和最小值分别为1,—1.---------------4分 (Ⅱ)解法1:令()sin()06f x x ππ=+=得,6x k k Z πππ+=∈,∵[1,1]x ∈- ∴16x =-或56x = ∴15(,0),(,0),66M N - -----------------------6分由sin()16x ππ+=,且[1,1]x ∈-得13x = ∴ 1(,1),3P -----------------------------8分∴11(,1),(,1),22PM PN =--=- ------------------------------------------10分∴cos ,||||PM PNPM PN PM PN ⋅<>=⋅35= .---------------------------------------13分解法2:过点P 作PA x ⊥轴于A ,则||1,PA = 由三角函数的性质知1||12MN T ==, ---------------6分||||2PM PN ===,-----------------------------------------------------------8分由余弦定理得222||||||cos ,2||||PM PN MN PM PN PM PN +-<>=⋅---------------------------10分=521345524⨯-=⨯.---13分解法3:过点P 作PA x ⊥轴于A ,则||1,PA =由三角函数的性质知1||12MN T ==,----------------------6分||||2PM PN ===----------------------------------------8分在Rt PAM ∆中,||cos ||PA MPA PM ∠===分 ∵PA 平分MPN ∠ ∴2cos cos 22cos 1MPN MPA MPA ∠=∠=∠-23215=⨯-=.------------------------------------------------------13分 17.解:(Ⅰ)玩家甲、乙双方在1次游戏中出示手势的所有可能结果是:(石头,石头);(石头,剪刀);(石头,布);(剪刀,石头);(剪刀,剪刀);(剪刀,布);(布,石头);(布,剪刀);(布,布).共有9个基本事件,--------------------3分玩家甲胜玩家乙的基本事件分别是:(石头,剪刀);(剪刀,布);(布,石头),共有3个.所以,在1次游戏中玩家甲胜玩家乙的概率3193P ==.--------------------6分 (Ⅱ)X 的可能取值分别为0,1,2,3.()303280327P X C ⎛⎫==⋅= ⎪⎝⎭,()1213121213327P X C ⎛⎫⎛⎫==⋅⋅=⎪ ⎪⎝⎭⎝⎭, ()212312623327P X C ⎛⎫⎛⎫==⋅⋅= ⎪⎪⎝⎭⎝⎭,()333113327P X C ⎛⎫==⋅=⎪⎝⎭.--------------------10分 X 的分布列如下:-------------------11分0123127272727EX =⨯+⨯+⨯+⨯=(或:1~(3,)3X B ,1313EX np ==⨯=).------------------13分18.解:方法一:(Ⅰ)证明:在△BCE 中,BC ⊥CF ,BC=AD =3,BE =3,∴EC= ∵在△FCE 中,CF 2=EF 2+CE 2,∴EF ⊥CE ………………3分 由已知条件知,DC ⊥平面EFCB ,∴DC ⊥EF ,又DC 与EC 相交于C ,……………………………………5分∴EF ⊥平面DCE ……………………6分(Ⅱ)过点B 作BH ⊥EF 交FE 的延长线于H ,连结AH . 由平面ABCD ⊥平面BEFC ,平面ABCD ∩平面BEFC=BC, AB ⊥BC ,得AB ⊥平面BEFC ,从而AH ⊥EF .所以∠AHB 为 二面角A-EF-C 的平面角.……8分在R t △CEF 中,因为EF =2,CF =4.EC=∴∠CEF =60°,由CE ∥BH ,得∠BHE =60°,又在Rt △BHE 中,BE =3,∴sin 2BH BE BEH =⋅∠=…………10分 由二面角A-EF-C 的平面角∠AHB=60°,在Rt △AHB 中,解得9tan 2AB BH AHB =⋅∠=, 所以当92AB =时,二面角A-EF-C 的大小为60°……………………13分 方法二:(Ⅰ)同解法一(Ⅱ)如图,以点C 为坐标原点,以CB ,CF 和CD 分别作为x 轴,y 轴和z 轴,建立空间直角坐标系C-xyz .……………………7分设AB=a (a >0),则C (0,0,0),A,0,a ),B0,0),E3,0),F (0,4,0).从而(3,1,0),(0,3,),EF AE a =-=-………………9分设平面AEF 的法向量为(,,)n x y z =,由0,0EF n AE n ⋅=⋅=得,30y y az ⎧+=⎪⎨-=⎪⎩,取x =1,则y z ==,即(1,3,n =,…………………………11分A B EFCHD不妨设平面EFCB 的法向量为(0,0,)BA a =,由条件,得1|cos ,|2||||n BA n BA n BA a ⋅<>===解得92a =.所以当92AB =时,二面角A-EF-C 的大小为60°.………………13分 19.解:(Ⅰ)依题意N (k,-l ),且∵klmn ≠0及MP 、NP 与x 轴有交点知:……2分M 、P 、N 为不同点,直线PM 的方程为()n ly x m n m k-=-+-,……3分 则E nk ml x n l -=-,同理可得F nk mlx n l+=+.……5分 (Ⅱ)∵M,P 在圆C :x 2+y 2=R 2上,222222m R n k R l⎧=-∴⎨=-⎩,222222222222222()()E F n k m l n R l R n l x x R n l n l ----⋅===--(定值). ∴E F x x ⋅的值是与点M 、N 、P 位置无关. ……8分同理∵M,P 在椭圆C :22221(0)x y a b a b+=>>上,2222222222a n m a b a lk a b ⎧=-⎪⎪∴⎨⎪=-⎪⎩,2222222222222222222()()E F a l a n n a a l n k m l b b x x a n l n l ----⋅===--(定值). ∴E F x x ⋅的值是与点M 、N 、P 位置无关. ………11分 (Ⅲ)一个探究结论是:0E F x x +=. ………13分 证明如下:依题意, E nk ml x n l -=-,F nk mlx n l+=+. ∵M,P 在抛物线C :y 2=2px (p >0)上,∴n 2=2pm,l 2=2pk.2222222()2(22)0E F n k ml pmk pmk x x n l n l --+===--.∴E F x x +为定值.:(Ⅰ)F (x )= e x +sinx -ax,'()cos xF x e x a =+-.因为x =0是F (x )的极值点,所以'(0)110,2F a a =+-==.………2分又当a =2时,若x <0, '()cos 0xF x e x a =+-<;若 x >0, '()cos 0xF x e x a =+->.∴x =0是F (x )的极小值点, ∴a=2符合题意. ………4分(Ⅱ) ∵a =1, 且PQ //x 轴,由f (x 1)=g (x 2)得:121sin xx e x =+,所以12111sin xx x e x x -=+-. 令()sin ,'()cos 10xxh x e x x h x e x =+-=+->当x >0时恒成立. ∴x ∈[0,+∞)时,h (x )的最小值为h (0)=1.∴|PQ|mi n =1. ………9分 (Ⅲ)令()()()2sin 2.xxx F x F x e e x ax ϕ-=--=-+-则'()2cos 2.xxx e ex a ϕ-=++-()''()2sin x x S x x e e x ϕ-==--.因为'()2cos 0x xS x e e x -=+-≥当x ≥0时恒成立, ………11分所以函数S (x )在[0,)+∞上单调递增, ………12分 ∴S (x )≥S (0)=0当x ∈[0,+∞)时恒成立;因此函数'()x ϕ在[0,)+∞上单调递增, '()'(0)42x a ϕϕ≥=-当x ∈[0,+∞)时恒成立. 当a ≤2时,'()0x ϕ≥,()x ϕ在[0,+∞)单调递增,即()(0)0x ϕϕ≥=. 故a ≤2时F (x )≥F(-x )恒成立. ………13分[)[)[)[)(]00002'()0,'()0,(0,),0'()0.()0,(0)0(0,)()0(14)()00,2.a x x x x x x x x x x F x F x x a a ϕϕϕϕϕϕ><+∞∴∈+∞<=∴∈<--≥∈+∞⋯∴>∞⋯⋯当时,又在单调递增,总存在使得在区间,上导致在递减,而,当时,,这与对恒成立不符,不合题意.综上取值范围是-,2分21.(1)解:设M =a b cd ⎡⎤⎢⎥⎣⎦,则a b c d ⎡⎤⎢⎥⎣⎦11⎡⎤⎢⎥⎣⎦=311⎡⎤⎢⎥⎣⎦=33⎡⎤⎢⎥⎣⎦,故3,3.a b c d +=⎧⎨+=⎩……………3分a b c d ⎡⎤⎢⎥⎣⎦12-⎡⎤⎢⎥⎣⎦=915⎡⎤⎢⎥⎣⎦,故29,215.a b c d -+=⎧⎨-+=⎩……………5分 联立以上两方程组解得a =1-,b =4,c =3-,d =6,故M =1436-⎡⎤⎢⎥-⎣⎦. ………7分 (2)解:曲线C 的直角坐标方程是22(2)4x y -+=,……3分 因为222x y ρ+=,cos y ρθ=,…5分故曲线C 的极坐标方程为24cos 0ρρθ-=,即4cos ρθ=.……7分 (3)解:令214y x x =+--,则1521334254x x y x x x x ⎧---⎪⎪⎪=--<<⎨⎪⎪+⎪⎩, ,, ,, .≤≥ .......3分 作出函数214y x x =+--的图象,它与直线2y =的交点为(72)-,和523⎛⎫ ⎪⎝⎭,........6分 所以2142x x +-->的解集为5(7)3x x ⎛⎫--+ ⎪⎝⎭,,........7分。
准考证号 姓名 .(在此卷上答题无效)2021年3月福州市高中毕业班质量检测注意事项:1. 答题前,考生务必在试题卷、答题卡规定的地方填写自己的准考证号、姓名.考生要认真核对答题卡上粘贴的条形码的“准考证号、姓名”与考生本人准考证号、姓名是否一致.2. 第Ⅰ卷每小题选出答案后,用2B 铅笔把答题卡上对应题目的答案标号涂黑.如需改动,用橡皮擦干净后,再选涂其它答案标号.第Ⅱ卷用0.5毫米黑色签字笔在答题卡上书写作答.在试题卷上作答,答案无效. 3. 考试结束,考生必须将试题卷和答题卡一并交回.第Ⅰ卷一、单项选择题:本题共8小题,每小题5分,共40分.在每小题给出的四个选项中,只有一项是符合题目要求的.1. 已知集合{}{}1234521A B x x k k A ===+∈,,,,,,,则A B =A .{}13,B .{}24,C .{}35,D .{}135,,【答案】C .【解答】由题意得{}3,5,7,9,11B =,所以{}3,5AB =,故选B .【命题意图】本小题以集合为载体,主要考查集合的概念和基本运算等基础知识;考查运算求解能力、推理论证能力;考查数学运算、逻辑推理等数学核心素养,体现基础性. 2. 设复数i z a b =+(,a b ∈∈Z Z ),则满足11z -≤的复数z 有A .7个B .5个C .4个D .3个【答案】B .【解答】由复数的几何意义可知,满足11z -≤的复数z 表示到点()1,0的距离不大于1的点.满足条件的点分别是()()()()()0,0,1,0,2,0,1,1,1,1-,共5个点,应选B .【命题意图】本小题以复数为载体,主要考查复数的基本概念和几何意义等基础知识;考查运算求解能力、推理论证能力;考查数形结合思想;考查数学运算、逻辑推理、直观想象等数学核心素养,体现基础性. 3. “5m ≤”是“2450m m --≤”的A .充分而不必要条件B .必要而不充分条件C .充分必要条件D .既不充分也不必要条件【答案】B .【解答】2450m m --≤⇔15m -≤≤.所以“5m ≤”是“2450m m --≤”的必要而不充分条件.应选B .【命题意图】本小题以不等关系为载体,主要考查一元二次不等式的解、充要条件等基础知识;考查运算求解能力、推理论证能力;考查化归与转化思想;考查数学运算、逻辑推理等数学核心素养,体现基础性.4. 若抛物线2y mx =上一点(),2t 到其焦点的距离等于3,则A .14m =B .12m =C .2m =D .4m =【答案】A .【解答】抛物线的方程可化为21x y m =,结合抛物线定义得1234m +=,解得14m =,故22t =±.应选A .【命题意图】本小题以抛物线为载体,主要考查抛物线的方程与定义等基础知识;考查运算求解能力、推理论证能力;考查数形结合思想;考查数学运算、逻辑推理等数学核心素养,体现基础性.5. 已知函数()ln f x x =,则函数1()1y f x=-的图象大致为【答案】D .【解答】()11ln ln 111f x x x ⎛⎫==-- ⎪--⎝⎭,其定义域为()1-∞,,为增函数,故选D . 【命题意图】本小题以对数函数为载体,考查函数性质、图象变换等基础知识;考查抽象概括能力、推理论证能力;考查数形结合思想;考查直观想象、逻辑推理等核心素养,体现基础性和综合性.6. 在ABC △中,E 为AB 边的中点,D 为AC 边上的点,BD ,CE 交于点F .若AF =3177AB AC +,则ACAD 的值为 A .2 B .3C .4D .5【答案】C .【解答】解法一:设AC AD λ=,所以AF =37AB +17AC =377AB AD λ+,因为F B D ,,三点共线,所以3177λ+=,解得4λ=,故4ACAD=.应选C . 解法二:设BF BD AD AC λμ==,,则()BF AD AB AB AC λλλμ=-=-+,所以AF =()1AB BF AB AC λλμ+=-+.又因为3177AF AB AC =+,所以31717λλμ⎧-=⎪⎪⎨⎪=⎪⎩,,解得14μ=,故4ACAD=.应选C . 【命题意图】本小题以三角形为载体,考查平面向量的线性运算、平面向量基本定理等基础知识;考查推理论证能力、运算求解能力;考查数形结合思想、函数与方程思想;考查直观想象、逻辑推理等核心素养,体现基础性和综合性.7. 分形几何学是一门以不规则几何形态为研究对象的几何学.如图,有一列曲线01n P P P ,,,,.已知0P 是边长为1的等边三角形,1k P +是对k P 进行如下操作而得到:将k P 的每条边三等分,以每边中间部分的线段为边,向外作等边三角形,再将中间部分的线段去掉(012k =,,,).记n P 的周长为n L 、所围成的面积为n S .对于n ∀∈N ,下列结论正确的是A .n n S L ⎧⎫⎨⎬⎩⎭为等差数列B .n n S L ⎧⎫⎨⎬⎩⎭为等比数列C .0M ∃>,使n L M <D .0M ∃>,使n S M <【答案】D .【解答】易知封闭曲线的周长数列{}n L 的首项03L =,公比为43.故433nn L ⎛⎫=⨯ ⎪⎝⎭,易知k P 边数为34k⨯,边长为13k ,故1k P +较k P面积增加21143439kk k +⎛⎫⎛⎫⨯ ⎪ ⎪⎝⎭⎝⎭,所以()1490,1,2,k kk S S k +⎛⎫⎪⎝=⎭=,累加可得49nn S ⎛⎫= ⎪⎝⎭.易知A ,B 均错误;当+n →∞时,43+3nn L ⎛⎫=⨯→∞ ⎪⎝⎭,所以C错误,而n S ,所以D 正确.综上,应选D .另解:由该曲线系列都在正三角形的外接圆内可知:0M ∃>,使n S M <.应选D . 【命题意图】本小题以数列为载体,考查数列求通项、递推数列等基础知识;考查推理论证能力、运算求解能力、创新意识;考查数形结合思想、化归与转化思想;考查数学抽象、逻辑推理、直观想象、数学运算等核心素养;体现综合性与创新性. 8. 已知函数()()2sin f x x ωϕ=+(π0,2ωϕ><)的图象过点()0,1,在区间ππ123⎛⎫⎪⎝⎭,上为单调函数,把()f x 的图象向右平移π个单位长度后与原来的图象重合.设12,x x ∈π5π,26⎛⎫⎪⎝⎭且12x x ≠,若()()12f x f x =,则()12f x x +的值为 A.B .1-C .1D【答案】C .【解答】依题意,()01f =,即2sin 1ϕ=,故1sin 2ϕ=,又π2ϕ<,所以π=6ϕ,所以()π2sin 6f x x ω⎛⎫=+ ⎪⎝⎭.因为把()f x 的图象向右平移π个单位长度后与原来的图象重合,所以()ππ2sin π2sin 66x x ωω⎛⎫⎛⎫-+=+ ⎪ ⎪⎝⎭⎝⎭,故π2πk ω=,即()2k k ω=∈Z .若()f x 在ππ123⎛⎫⎪⎝⎭,上为单调函数,则ππππ31242T ω-==≤,所以04ω<≤,所以2ω=,或4.经验证,当2ω=时,()f x 在ππ123⎛⎫⎪⎝⎭,上不是单调函数;当4ω=时,满足题意.综上,()π2sin 46f x x ⎛⎫=+ ⎪⎝⎭,它在π5π,26⎛⎫ ⎪⎝⎭上的对称轴为7π12x =,所以127π12x x +=⨯7π26=,所以()127ππ2sin 4166f x x ⎛⎫+=⨯+= ⎪⎝⎭. 【命题意图】本小题以三角函数的图象为载体,考查三角函数的图象与性质等基础知识;考查数形结合思想、函数与方程思想;考查逻辑推理、直观想象、数学运算等核心素养;体现基础性与综合性.二、多项选择题:本题共4小题,每小题5分,共20分.在每小题给出的四个选项中,有多项符合题目要求.全部选对的得5分,部分选对的得3分,有选错的得0分. 9. “一粥一饭,当思来之不易”,道理虽简单,但每年我国还是有2 000多亿元的餐桌浪费,被倒掉的食物相当于2亿多人一年的口粮.为营造“节约光荣,浪费可耻”的氛围,某市发起了“光盘行动”.某机构为调研民众对“光盘行动”的认可情况,在某大型餐厅中随机调查了90位来店就餐的客人,制成如右所示的列联表,通过计算得到2K 的观测值为9.已知()2 6.6350.010P K =≥,()210.8280.001P K =≥,则下列判断正确的是A .在该餐厅用餐的客人中大约有66.7%的客人认可“光盘行动”B .在该餐厅用餐的客人中大约有99%的客人认可“光盘行动”C .有99%的把握认为“光盘行动”的认可情况与年龄有关D .在犯错误的概率不超过0.001的前提下,认为“光盘行动”的认可情况与年龄有关 【答案】AC .【解答】对于选项A ,随机调查的90人中认可“光盘行动”的有60人,所以大约有66.7%的客人认可“光盘行动”,故正确,从而易知选项B 错误;因为6.635910.828<<,所以有99%的把握认为“光盘行动”的认可情况与年龄有关,所以选项C 正确,从而选项D 错误.综上,应选AC .【命题意图】本小题以“光盘行动”为载体,考查独立性检验等基础知识;考查数据处理能力、应用意识;考查或然与必然思想;考查逻辑推理、数据分析等核心素养;体现基础性与应用性.10. 如图,在下列四个正方体中,A B ,为正方体的两个顶点,M N P ,,为所在棱的中点,则在这四个正方体中,直线AB ∥平面MNP 的是【答案】ABD .【解答】对于选项A ,如图1,平面截正方体的截面为正六边形,各顶点为所在棱的中点,由AB PC ∥,可知AB ∥平面MNP .该选项正确;对于选项B ,由AB PN ∥可知AB ∥平面MNP .该选项正确; 对于选项C ,如图2,平面ACBD平面PMN PQ ,若AB ∥平面MNP ,则AB PQ ∥,由Q 为AD 四等分点,P 为BD 中点知,AB PQ ∥,从而AB ∥平面MNP .该选项错误.对于选项D ,如图3,由平面ACBD ∥平面MNP 可知AB ∥平面MNP .该选项正确. 综上,应选ABD .图1图2图3【命题意图】本小题以正方体为载体,主要考查空间中直线与直线、直线与平面、平面与平面的平行关系等基础知识;考查空间想象能力、推理论证能力;考查化归与转化思想;考查直观想象、逻辑推理等核心素养,体现基础性.A B C D11. 已知P 是双曲线:E 22145x y -=在第一象限上一点,12F F ,分别是E 的左、右焦点,12PF F △的面积为152.则以下结论正确的是 A .点P 的横坐标为52B .12π3F PF ∠<<π2C .12PF F △的内切圆半径为1D .12F PF ∠平分线所在的直线方程为3240x y --= 【答案】BCD .【解答】依题意,121211156222PF F P P S F F y y =⋅=⨯=△,所以532P P y x ==,,选项A 错误;依题意,()()123030F F -,,,,则2PF ⊥x 轴,所以1212212tan 5F F F PF PF ∠==,所以12π3F PF ∠<<π2,选项B 正确;从上述讨论及双曲线定义可得2155134222PF PF ==+=,,设12PF F △的内切圆半径为r ,则1215136222PF F S r ⎛⎫=⨯++= ⎪⎝⎭△152,所以1r =,所以选项C正确;12PF F △的内心为()21I ,,从而12F PF ∠平分线所在的直线,即直线PI 的方程为1253212y x --=--,即3240x y --=,选项D 正确.综上,应选BCD . 【命题意图】本小题以双曲线为载体,主要考查双曲线的定义、直线方程、直线与双曲线的位置关系等基础知识;考查运算求解能力、推理论证能力;考查数形结合思想、化归与转化思想;考查直观想象、逻辑推理、数学运算等核心素养,体现基础性和综合性. 12. 在数学中,双曲函数是一类与三角函数类似的函数.最基本的双曲函数是双曲正弦函数sinh x =e e 2x xx -+=等.双曲函数在物理及生活中有着某些重要的应用,譬如达·芬奇苦苦思索的悬链线(例如固定项链的两端,使其在重力的作用下自然下垂,那么项链所形成的曲线即为悬链线)问题,可以用双曲余弦型函数来刻画.则下列结论正确的是 A .22cosh +sinh 1x x =B .cosh y x =为偶函数,且存在最小值C .()0000sinh sinh sinh x x x ∀>,> D .12x x ∀∈R ,,且12x x ≠,1212sinh sinh 1x x x x -->【答案】BCD .【解答】因为2222e e e e e e 222x x x x x x---⎛⎫⎛⎫+-++ ⎪⎭=⎪⎝⎝⎭,所以选项A 错误; ()e e cosh cosh 2x x x x -+-==,e e cosh 122x x x -+==≥,当且仅当0x =时cosh x 取到最小值1,所以选项B 正确;令()sinh F x x x =-,即()e e 2x xx x F -=--,则()e +e 102x x F x -'=-≥,()F x 在R 上单调递增,所以当0x >时,()()00F x F =>,故0000sinh x x x ∀>,>,又因为sinh y x =单调递增,所以()0000sinh sinh sinh x x x ∀>,>,所以选项C 正确; 不妨设12x x >,则()()12F x F x >,即1122sinh sinh x x x x -->,亦即1sinh x -2sinh x >12x x -,故1212sinh sinh 1x x x x -->,所以选项D 正确.【命题意图】本小题以函数为载体、考查指数的运算、函数的基本性质、导数与函数的单调性的关系等基础知识;考查抽象概括能力、推理论证能力、创新意识;考查数形结合思想、化归与转化思想、特殊与一般思想;考查数学抽象、逻辑推理、数学运算、直观想象等核心素养;体现综合性与创新性.第Ⅱ卷注意事项:用0.5毫米黑色签字笔在答题卡上书写作答.在试题卷上作答,答案无效. 三、填空题:本大题共4小题,每小题5分,共20分.把答案填在题中的横线上. 13. 设x y ,满足约束条件402600x y x y y +-⎧⎪+-⎨⎪⎩≤,≥,≥,则2x y -的取值范围为 .【答案】[]24-,. 【解答】作出可行域如图所示,当目标函数2z x y =-经过()22A ,时,z 取得最小值2222-⨯=-,当目标函数2z x y=-经过()40B ,时,z 取得最大值4204-⨯=.故2x y -的取值范围为[]24-,. 【命题意图】本小题以不等式为载体,主要考查线性规划等基础知识;考查运算求解能力、推理论证能力;考查数形结合思想;考查直观想象、数学运算等核心素养,体现基础性.14. 51x x ⎛⎫+ ⎪⎝⎭的展开式中,1x 的系数为 . 【答案】5.【解答】依题意,展开式中第1k +项为135522155kk kkk k T C x x C x ---+⎛⎫== ⎪⎝⎭,令3512k -=-得4k =,所以1x的系数为41555C C ==. 【命题意图】本小题以二项式为载体,主要考查二项式定理等基础知识;考查运算求解能力、推理论证能力;考查数学运算、逻辑推理等核心素养,体现基础性.15. 在三棱锥P ABC -中,侧面PAC 与底面ABC 垂直,9030BAC PCA ∠=︒∠=︒,,3AB =,2PA =.则三棱锥P ABC -的外接球的表面积为 .【答案】25π.【解答】依题意,BA ⊥平面PAC ,将三棱锥P ABC -补成直三棱柱111PAC P A C -,则其外接球即为所求,设外接球的球心为O ,PAC △的外心为1O ,则11322OO AB ==,又1122sin PAO A PCA=⋅=∠,所以外接球的半径221152R OO O A =+=,所以所求外接球的表面积为24π25πR =. 【命题意图】本小题以空间几何体为载体,主要考查多面体的外接球等基础知识;考查空间想象能力、推理论证能力、运算求解能力;考查数形结合思想、化归与转化思想;考查直观想象、逻辑推理、数学运算等核心素养,体现基础性和综合性.16. 已知圆C 的方程为()()22214x y -+-=,过点()20M ,的直线与圆C 交于,P Q 两点(点Q 在第四象限).若2QMO QPO ∠=∠,则点P 的纵坐标为 . 【答案】12. 【解答】解法一:因为2QMO QPO ∠=∠,所以MOP MPO ∠=∠,所以2MP MO ==,所以P 在圆()2224x y -+=上,联立两圆方程解得12P y =. 解法二:因为2QMO QPO ∠=∠,所以MOP MPO ∠=∠,所以2MP MO ==.另一方面圆C 的半径2CP =,且CM x ⊥轴,故1122P C y y ==. 【命题意图】本小题以圆为载体,主要考查直线与圆的位置关系等基础知识;考查运算求解能力、推理论证能力;考查数形结合思想、函数与方程思想;考查直观想象、逻辑推理、数学运算等核心素养,体现基础性和综合性.四、解答题:本大题共6小题,共70分.解答应写出文字说明、证明过程或演算步骤. 17. (本小题满分10分)在①21n n S a =+;②()1211,log 21n n a a a n +=-=-;③212n n n a a a ++=,23S =-,34a =-这三个条件中任选一个,补充在下面问题的横线上,并解答.问题:已知单调数列{}n a 的前n 项和为n S ,且满足 . (1)求{}n a 的通项公式;(2)求数列{}n na -的前n 项和n T .【命题意图】本小题主要考查等比数列、n a 与n S 的关系、数列求和等基础知识;考查推理论证能力、运算求解能力;考查化归与转化思想、函数与方程思想;考查逻辑推理、数学运算等核心素养,体现基础性、综合性.满分10分.【解答】(1)选①,即21n n S a =+.(ⅰ)则当1n =时,1121S a =+,故11a =-; ························································ 1分 当2n ≥时,1121n n S a --=+,(ⅱ)(ⅰ)(ⅱ)两式相减得12n n a a -=, ···························································· 3分 所以{}n a 为等比数列,其中公比为2,首项为1-. ····································· 4分 所以12n n a -=-. ·················································································· 5分 选②,即()1211,log 21n n a a a n +=-=-.所以当2n ≥时,()()2121log log 2n n n n a a a a +--=, ········································ 1分 即114n n a a +-=, ······················································································· 2分 所以{}21k a -(*k ∈N )为等比数列,其中首项为11a =-,公比为4, 所以()211121142k k k a ----=-⨯=-. ······························································ 3分由()12121,log 1a a a =-=,得22a =-,同理可得,1212242k k k a --=-⨯=-(*k ∈N ). ············································· 4分 综上,12n n a -=-. ··············································································· 5分选③,即212n n n a a a ++=,23S =-,34a =-.所以{}n a 为等比数列,设其公比为q , ····················································· 1分 则()121134a q a q +=-⎧⎪⎨=-⎪⎩,,解得112a q =-⎧⎨=⎩,,或192.3a q =-⎧⎪⎨=-⎪⎩, ············································ 3分 又因为{}n a 为单调数列,所以0q >,故112a q =-⎧⎨=⎩,, ····································· 4分所以12n n a -=-. ·················································································· 5分 (2)由(1)知,12n n na n --=⋅, 所以()22112232122n n n T n n --=+⨯+⨯++-⋅+⋅, ····································· 6分 ()()221222222122n n n n T n n n --=+⨯++-⋅+-⋅+⋅, ······················· 7分 两式相减得221122222n n n n T n ---=+++++-⋅ ········································· 8分()212n n n =--⋅. ···························································· 9分所以()121n n T n =-⋅+. ······································································ 10分 18. (本小题满分12分)在ABC △中,内角A B C ,,所对的边分别为a b c ,,,cos cos a b c B b C +=-. (1)求角C 的大小;(2)设CD 是ABC △的角平分线,求证:111CA CB CD+=. 【命题意图】本小题主要考查解三角形等基础知识;考查推理论证能力、运算求解能力;考查函数与方程思想、数形结合思想;考查直观想象、逻辑推理、数学运算等核心素养,体现基础性、综合性.满分12分.【解答】解法一:(1)因为cos cos a b c B b C +=-,由正弦定理得sin sin =sin cos sin cos A B C B B C +-, ···································· 2分 因为()()sin sin πsin B C A A +=-=,所以()sin +sin sin cos sin cos B C B C B B C +=-, ·········································· 3分 所以2sin cos sin 0B C B +=, ·································································· 4分因为()0,πB ∈,所以sin 0B ≠,所以1cos 2C =-,······································· 5分又()0,πC ∈,所以2π3C =. ····································································· 6分 (2)因为CD 是ABC △的角平分线,且2π3C =, 所以π3ACD BCD ∠=∠=. ··········································· 7分 在ABC △中,ABC ACD BCD S S S =+△△△,则由面积公式得12π1π1πsin sin sin 232323CA CB CA CD CD CB ⋅=⋅+⋅, ···································· 10分 即CA CB CA CD CD CB ⋅=⋅+⋅. ······························································· 11分 两边同时除以CA CB CD ⋅⋅得111CA CB CD+=. ············································ 12分 解法二:(1)因为cos cos a b c B b C +=-,由余弦定理得22222222a c b a b c a b c b ac ab +-+-+=⋅-⋅, ··································· 2分 整理得()22222a a b c b +=-,即2220a b c ab +-+=, ································· 3分 所以()12cos 0ab C +=, ········································································ 4分所以1cos 2C =-, ················································································· 5分又()0,πC ∈,所以2π3C =. ····································································· 6分 (2)因为CD 是ABC △的角平分线,且2π3C =,所以π3ACD BCD ∠=∠=. ····································································· 7分 在ABC △中,由正弦定理得2πsin sin sin 3CA CB ABB A ==, ········································································· 8分 即ππsin sin sin sin 33CA CB AD DBB A ==+. ···································· 9分同理在CAD △和CBD △中,得πsin sin 3CD AD A =,πsin sin 3CD DB B =, 所以sin sin sin CA CD CDB A B =+,即sin sin CA CD CD B A -=, ······································· 10分故CA CD CDCA CB -=,即1+CD CD CB CA =, ····················································· 11分 故111CA CB CD+=. ············································································ 12分 解法三:(1)同解法一. ······································································· 6分(2)设CB CA ==a b ,,则2π1cos 32ab ab ⋅==-a b , ·································· 7分 因为CD 为ABC △的角平分线,所以AD AC b BC BC a==, ·································· 8分 所以()b bAD AB a b a b==-++a b , ·························································· 9分 所以b aCD CA AD a b a b=+=+++a b ,即()a b CD a b +=+b a ,···················· 10分 两边同时平方得()()()()()222222a b CD ab ba ab ab +=++⋅=a b ,即()a b CD ab +=, ············································································ 11分 所以111a b CD ab b a +==+,即111CA CB CD+=. ·········································· 12分 注:用初中引平行线证明同样给分.19. (本小题满分12分)如图,在三棱台111ABC A B C -中,1111112AA A C CC AC A C AB ====⊥,,. (1)求证:平面11ACC A ⊥平面11ABB A ;(2)若901BAC AB ∠=︒=,,求二面角1A BB C --的正弦值.【命题意图】本小题主要考查空间直线与直线、直线与平面、平面与平面的位置关系等基础知识;考查推理论证能力、运算求解能力与空间想象能力;考查数形结合思想;考查直观想象、逻辑推理、数学运算等核心素养,体现基础性、综合性.满分12分.【解答】(1)依题意,四边形11ACC A 为等腰梯形,过11A C ,分别引AC 的垂线,垂足分别为D E ,,则()()1111111212222AD AC A C AA =-=⨯-==,故160A AC ∠=︒.在1ACA △中,22222111112cos 1221232A C A A AC A A AC A AC =+-⋅∠=+-⨯⨯⨯=, 所以22211A C A A AC +=,故190AA C ∠=︒,即11A C AA ⊥. ····························· 2分 因为11A C AB AB AA A ⊥=,,且1AB AA ⊂,平面11ABB A , 所以1A C ⊥平面11ABB A , ······································································· 4分 因为1A C ⊂平面11ACC A ,所以平面11ACC A ⊥平面11ABB A . ···························································· 5分 (2)因为11AB AC A C AB AC A C C ⊥⊥=,,,且1AC A C ⊂,平面11ACC A ,所以AB ⊥平面11ACC A ,结合(1)可知1AB AC A D ,,三条直线两两垂直. ······ 6分以A 为原点,分别以1AB AC DA ,,的方向为x y z ,,轴的正方向,建立空间直角坐标系A xyz -,如图所示,则各点坐标为()()()1100010002002A B C A ⎛ ⎝⎭,,,,,,,,,,,133022C ⎛⎫⎪ ⎪⎝⎭,,. ························································································· 7分 由(1)知,()11223300312233A C ⎛⎫==-=- ⎪ ⎪⎝⎭n ,,,,为平面11ABB A 的法向量. ········································· 8分()113120022BC C C ⎛⎫=-=- ⎪ ⎪⎝⎭,,,,,, 设()2x y z =n ,,为平面11BCC B 的法向量,则 221BC C C ⎧⊥⎪⎨⊥⎪⎩n n ,,故2212013022BC x y C C y z ⎧⋅=-+=⎪⎨⋅=-=⎪⎩n n ,,取()22331=n ,,, ···················· 10分 所以121212311cos 244⋅-===⨯n n n n n n ,, ···················································· 11分 设二面角1A BB C --的大小为θ,则2115sin 144θ⎛⎫=--= ⎪⎝⎭. ·················· 12分20. (本小题满分12分)已知椭圆2222:1x y E a b+=(0a b >>)的左、右顶点分别为()()122020A A -,,,,上、下顶点分别为12B B ,,四边形1221A B A B 的周长为43. (1)求E 的方程;(2)设P 为E 上异于12A A ,的动点,直线1A P 与y 轴交于点C ,过1A 作12A D PA ∥,交y 轴于点D .试探究在x 轴上是否存在一定点Q ,使得3QC QD ⋅=,若存在,求出点Q 坐标;若不存在,说明理由.【命题意图】本小题主要考查直线与椭圆的位置关系等基础知识;考查推理论证能力、运算求解能力;考查函数与方程思想、数形结合思想、化归与转化思想;考查直观想象、逻辑推理、数学运算等核心素养,体现基础性、综合性与创新性.满分12分.【解答】解法一:(1)依题意,2a =. ················································· 1分 由椭圆的对称性可知,四边形1221A B A B 为菱形,其周长为22443a b +=. ···· 3分 所以1b =, ························································································ 4分。
参考答案-、选择题 1 . C 2 . A 3 . C 4 . B 5 . B 6 . A 8 . C 9 . B 10 . A11 . B 12 . A 二、填空题4 •主? 15 .(理)82 ;(文) 916~3.①②③三、解答题 17.解:T A 、 B > <2是厶ABC 勺三个内角•••A+B+C =Tt•・y = tB Ccos — 2 B C2si n2^~Ccos —2A tg iBC 2(s in cos 2 2 o B C 2cos cos2B . cos sin 2 2tg|+ Atg 2因此,任意交换两个角的位置,18.解:(I )设 X 1 Vx 2 tg2y 的值不变.10则 f(x 1)—f(x2) 2X1 +1)(2 x12x1)(12aL•「X 1Vx 2 , •2为2 又••• a V0,「.1 —2.•.当 a <0时, f (x •••当 a <0时,y = f(n)设P ( x , y )是函数X 1a X i X 22 x 1)—f(x )是R 上的增函数 y =g (x )的图象上的一点,X2V (x 2)v 0 即 fV f ( x 2) 分(x 1) 4P(x , y )关于直线x =1成对称的点为P'(x ',y')x x' 1 则T1y y' 由已知有 • • y = 2y 2-x—1y'=2 —1(x )=2 2-x(川)•••(x)=0=2V 0 x a••• 2X12Xa = 0△= (— 1)2—4a=1—4a>01 1 4a2x■ 1 4a分•••当aVO 时,1V ..1 4a •••2 x = 1一上没有实数解.2 由 2 x = 11 4a 2解得: x =log 2 1_J__4a2•••当aVO 时,f ( x )= O 的解为 x =log -_—_4a 分219. (I)证:取AC 中点D,连ED ••• E 是AB 的中点1• ED // — B'C . 22••• E ' C 丄 AC•DE 丄AC 2 分又'/△ABC 是底角等于30°的等腰三角形 • ED 丄AC 3 分BD A DE = D 「.AC 丄面 BDE• AC 丄BE ,即AC 丄BA' 4 分ED =BD =A D •tg3 0 =2在厶BDE 中,由余弦定理得:2八+ BD —2 ED •2EB = EDBD cos4=2+4—2•△ BDE 是等腰直角三角形, DE 丄BE ED 是异面直线 AC 与BA 的距离为 运 8 分 (川)连A' D ■/EB =EA '=ED = ,2• A ' D 丄 BD 又AC 丄面BEDA'D 面BED • A ' D ± AC • A ' D 丄面 ABC M A ' D =2V B'— ABC =A ' D=丄】(BD AC) A'D3 2 =8 .3 11 分3V B '—BEC=V C —BEB'=2V CABB' 2V B 'ABC(H )解:由(I )小题知/EDB 是二面角B '— AC — B 的一个平面角1)20.解:(I )2000年底除了危旧住房和新型住房外的其它形式的住房面积为 a -( - l )a -a 1 分4 312每年拆除危旧住房面积为 1 1 a ——a 10 330a a1=(1 4 20%)5 a 12a 一5 a 2= (1 20%)2a 4 12a5 a 3= (1 20%)3a4 12一般地依题意,得: -a ------- ------a3 10 31 2a — a3 301 a 3 a 4分3301 1 1 10 nan5a -(1 20%)—412 a , 亠,、n5a-(1 20%)412 30 a n =a(1 10)(n ),a由- (1 20%) n 5a 4a412an43得— 1.2na 41211) (n n Ig 1.2 Ig 43 Ig 3 Ig 43 Ig 3 n14.372lg 2 Ig 3 1 n 15取 15 105 答:至少再经过5年才能使该地区的居民住房总面积翻两番 .12分21.解:(I ):a n?2n 1 n当n >2时,a a 3 3a n 1n 1 a 2(n 1} 1 ②由①一②得弐n•'•a n =(a 2—1) n 当n = 1时,由已知得a --a n^( a 1)n(n) S n =( a 2—1) I ① 2na[a 2(n °n 1] a 2(a 2 1)2n — 2・a21=a2n —2・a [1 + 2 (n >2)—1 (n €N) a2+3(4分a 2)2 + 42) 3+-+(n — 1)2 n-2(a ) +n(a2) "J2 2• •a S n =(a — 1)①—②得:(1 — (a 2) T a >0且a 工12— 1^0 n= — [1 + a1 a 2n1 a 2aa 2)S n2、 2 / 2、 )+3(a)2a +2(a2(a —1) [1++ -+(n —1)(2、 2 / 2、 a )+…+(a )2) —1n —1/ 2、 n+ n(a ):—nna 2n2+(a2) 2+ -+(a2)—i(a 2)S n n im(a 2n1)n2na2n0(a 2 1(a 21)(川) (理)本题即a n a n 1 2 a n 2n n 1 n 2• a n an 1a n2 - 212分nn 1 n 2“ 2 八 2n 2“ 2 2n 2 八 2n 2 (a 1)a (a 1)a2(a 1)a (a 2 2n1)a2(1 2 a 2a 4)2n a 2 2(a1)(1 2a 2)(1 a 2) 2 2 2 2n 2(a 1) (1 2a )a 0(a 0) a n a n 1 2 n n 1 a n 2n 214 22.解:(理)(I )解:设椭圆 C: (x 1)22 笃 1(a b b 2 0)•/2C=2,A • ••右准线方程为 设M (x , y )、 连接PB 则| P 2 C =1 x = a 十 P ( x 0, 2 A | +| 0) •(| PA | 2• (2 a )—2・2 y o = ±(+ | PB | y PB | 2 -1) I 2 )-2| PA |・| PB |=4 I =4 AB 2由x a y y 0 消去a ,得y =±( x — 2)T0v| y 0 |<1,2•・0< a — 1<1, 1< 2 a < 2••2< x <3即M 点的轨迹方程是 y = ±( x —2) (2< x < 3 = 7分 (H)解:设 ZABQ = a , a €(- 4 ,2),则 8 分 | AB |=2,| P A | =| B Q | = 2co s a| PQ | = | AB | —2 | BQ | co s a = =2- -4 c 2 os a• •周长 L =(2—4c :os 2 、 a ) + 4c os a + 2 = — 4(co 10s(a 2 1)当cos a =[,即a =—时,周长L 取最大值5. 一 3 112 此时 | BQ |=1, I AQ |= 3 2 a =| BQ | + | AQ |=1 b 2 2 a 2 2 仝 2 •••所求椭圆C 的方程为(x 1)2 2y— 1 14 分 2 2 一 3 2(文)(I )解:设 D 为AB 中点,连接 DQ DR PB当丨PQ |= 1时,△ DPQ 为正三角形,边长为 1.从而 △DPA 、A DQE 也是边长为1的正三角形.•••I PA |=1,| PB |= ,3 /•2 a =| PA | + | PB |=1+3 312 2V3• -a=, a2 2又••• c = 1a 2 1y o(a 2 1)消去 a ,得 y =±( x —2) '^0<| y o |<1 ••0< a • •2< x <3即M 点的轨迹方程是 y =±( x — 2) (2< x <3 )14分异—c 2=异—1=2•椭圆C 的方程 〔为(x 1) 2 12_y_ 1 6 分2、 3321)2 22(n )解:设椭圆C: (x2;2 1(ab0)abV2 C =2,. C =1•右准线方程为 x 2=a+ 1 8 分又设M ( x , y ), P ( x o , y o )•••| PA | 2+| PB | 221 AB |•(| PA | 2+ | PB | 2)—2| PA |•|即(2a 2)— 2・ 2| y o |=4•- b2.•.y o = ±(a2—1)11 分PB=421<1,1< a <2。