上海市复旦附中2016-2017学年高二上学期期中考试数学试卷
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复旦附中高一期中数学卷2016.11一.填空题1.集合{1,2,3,,2015,2016}⋅⋅⋅的子集个数为2.已知全集U R =,集合{|1}A x x =≤,集合{|2}B x x =≥,则()U C A B =3.已知集合{|12}A x x =≤≤,集合{|}B x x a =≤,若A B ≠∅ ,则实数a 的取值范围是4.如果全集{,,,,,}U a b c d e f =,{,,,}A a b c d =,{}A B a = ,(){}U C A B f = ,则B =5.已知210a a >>,210b b >>,且12121a a b b +=+=,记1122A a b a b =+,1221B a b a b =+,12C =,则按A 、B 、C 从小到大的顺序排列是6.已知Rt ABC ∆的周长为定值2,则它的面积最大值为7.我们将b a -称为集合{|}M x a x b =≤≤的“长度”,若集合2{|}3M x m x m =≤≤+,{|0.5}N x n x n =-≤≤,且集合M 和集合N 都是集合{|01}x x ≤≤的子集,则集合M N 的“长度”的最小值是8.已知{|}A x x =>,{|(3)(3)0}B x x x x =-+>,则A B = 9.对于任意集合X 与Y ,定义:①{|X Y x x X -=∈且}x Y ∉,②()X Y X Y ∆=-()Y X -,已知2{|,}A y y x x R ==∈,{|22}B y y =-≤≤,则A B ∆=10.已知常数a 是正整数,集合1{|||,}2A x x a a x Z =-<+∈,{|||2,}B x x a x Z =<∈,则集合A B 中所有元素之和为11.非空集合G 关于运算*满足:①对任意,a b G ∈,都有a b G *∈;②存在e G ∈使对一切a G ∈都有a e e a a *=*=,则称G 是关于运算*的融洽集,现有下列集合及运算:①G 是非负整数集,*运算:实数的加法;②G 是偶数集,*运算:实数的乘法;③G 是所有二次三项式组成的集合,*运算:多项式的乘法;④{|,}G x x a a b Q ==+∈,*运算:实数的乘法;其中为融洽集的是12.集合{(,)|||,}A x y y a x x R ==∈,{(,)|,}B x y y x a x R ==+∈,已知集合A B 中有且仅有一个元素,则常数a 的取值范围是二.选择题13.已知集合{1,2,3,,2015,2016}A =⋅⋅⋅,集合{|31,}B x x k k Z ==+∈,则A B 中的最大元素是()A.2014 B.2015 C.2016 D.以上答案都不对14.已知全集U A B = 中有m 个元素,()()U U C A C B 中有n 个元素,若A B 非空,则A B 的元素个数为()A.mn B.n m - C.m n+ D.m n -15.命题“已知,x y R ∈,如果220x y +=,那么0x =且0y =”的逆否命题是()A.已知,x y R ∈,如果220x y +≠,那么0x ≠且0y ≠B.已知,x y R ∈,如果220x y +≠,那么0x ≠或0y ≠C.已知,x y R ∈,如果0x ≠或0y ≠,那么220x y +≠D.已知,x y R ∈,如果0x ≠且0y ≠,那么220x y +≠16.对任意实数,,a b c ,给出下列命题:①“a b =”是“ac bc =”的充要条件;②“5a +是无理数”是“a 是无理数”的充要条件;③“ab >”是“22a b >”的充分条件;④“4a <”是“3a <”的必要条件;其中真命题的个数是()A.1个 B.2个 C.3个 D.4个三.解答题17.已知集合{1,2,3}A =,2{|(1)0,}B x x a x a x R =-++=∈,若A B A = ,求实数a ;18.已知,,a b c R +∈,求证:3332222222()a b c ab a b bc b c ac a c ++≥+++++;19.设正有理数1a21211a a =++,求证:(1介于1a 与2a 之间;(2)2a 比1a ;20.已知对任意实数x ,不等式2(3)10mx m x --+>成立或不等式0mx >成立,求实数m 的取值范围;21.已知关于x 的不等式2(4129)(211)0kx k k x ---->,其中k R ∈;(1)试求不等式的解集A ;(2)对于不等式的解集A ,记B A Z = (其中Z 为整数集),若集合B 为有限集,求实数k 的取值范围,使得集合B 中元素个数最少,并用列举法表示集合B ;参考答案一.填空题1.201622.{|12}x x << 3.1a ≥ 4.{,}a e 5.B C A <<6.3-7.168.{|30}x x -<<9.[2,0)(2,)-+∞ 10.2a 11.①④12.[1,1]-二.选择题13.A14.D 15.C 16.B三.解答题17.1a =或2或3;18.略;19.略;20.0m >;21.(1)①当0k <,911{|3}442k A x x k =++<<;②当0k =,11{|}2A x x =<;③当01k <<或9k >,11{|2A x x =<或93}44k x k>++;④当19k ≤≤,9{|344k A x x k =<++或11}2x >;(2)0k <,{2,3,4,5}B =;。
6.关于x,y的二元线性方程组nx−3y=2的增广矩阵经过变换,最后得到的矩阵为22tanθ−sinθ=0有两个不等实根a和b,那么过点A a,a2,B b,b2的直线与圆2016年上海中学高二上学期数学期中考试试卷一、填空题(共12小题;共60分)1.已知A4,6,B−3,−1,C5,−5三点,则经过点A且与BC平行的直线l的点斜式方程为.2.已知a=1,b=2,且λa+b⊥2a−λb,a与b的夹角为60∘,则实数λ=3.直线x+3y+2=0与直线x+1=0的夹角为.y≥0,4.设变量x,y满足约束条件x−y+1≥0,则z=2x+y的最大值为.x+y−3≤0,5.圆心为1,2且与直线5x−12y−7=0相切的圆的方程为..2x+my=5,103011则m=.n7.对任意实数m,圆x2+y2−2mx−4my+6m−2=0恒过定点,则其坐标为.,2x74x8.在行列式4−34中,第3行第2列的元素的代数余子式记作f x,则y=1+f x的零65−1点是.9.已知定点A0,−5,P是圆x−22+y+32=2上的动点,则当PA取到最大值时,P点的坐标为.10.已知P是△ABC内的一点,且满足PA+3PB+5PC=0,记△ABP,△BCP,△ACP的面积依次为S1,S2,S3,则S1:S2:S3=.11.若直线y=x+b与曲线y=3−4x−x2有公共点,则实数b的取值范围是.12.已知a>1,x≥1,y≥1,且loga x+logay=logaa4x4+logaa4y4,则logaxy的取值范围是.二、选择题(共4小题;共20分)x y113.已知直线方程为351=0,则下列各点不在这条直线上的是 −231A.−2,3B.4,7C.3,5D.0.5,414.直线2x+3y−6=0关于点1,−1对称的直线方程是 A.2x+3y+7=0 C.2x+3y+8=0B.3x−2y+2=0 D.3x−2y−12=015.若O为△ABC的内心,且满足OB−OC⋅OB+OC−2OA=0,则△ABC的形状为 A.等腰三角形B.正三角形C.直角三角形D.以上都不对16.已知方程x2+x1x2+y2=1的位置关系是 A.相交B.相切C.相离D.随θ值的变化而变化三、解答题(共5小题;共65分)mx+y=−1,17.利用行列式解关于x,y的二元一次方程组3mx−my=2m+3.18.设两个向量a,b满足a=2,b=1,a,b的夹角为60∘,若向量2t a+7b与向量a+t b的夹角为钝角,求实数t的取值范围.19.已知直线l过点1,3,且与x轴、y轴都交于正半轴,求:(1)直线l与两坐标轴围成的图形的面积的最小值及此时直线l的方程;(2)直线l与两坐标轴截距之和的最小值及此时直线l的方程.20.已知A0,2是定圆C:x2+y2=16内的一个定点,D是圆上的动点,P是线段AD的中点,求:(1)P点所在的曲线方程E;(2)过点A且斜率为−3的直线与曲线E交于M,N两点,求线段MN的长度.421.在平面直角坐标系中,以原点O为圆心,r(r>0)为半径的定圆C,与过原点且斜率为k1(k≠0)的动直线交于P,Q两点,在x轴正半轴上有一个定点R m,0,P,Q,R三点构成三角形,求:(1△)PQR的面积S1的表达式,并求出S1的取值范围;(2△)PQR的外接圆C2的面积S2的表达式,并求出S2的取值范围.3− 2 2【解析】关于 x ,y 的二元线性方程组 nx − 3y = 2 的增广矩阵经过变换可化为:2x + my = 5, x = 3, 6 + m = 5,答案第一部分1. y − 6 = − 1 x − 42【解析】k BC = −1+5 = − 1,利用点斜式可得:y − 6 = − 1 x − 4 .2. −1 ± 3【解析】因为 λa + b ⊥ 2a − λb , 所以 λa + b ⋅ 2a − λb = 0,所以:2λa 2 + 2 − λ2 a ⋅ b − λb 2 = 0,所以 2λ × 1 + 2 − λ2 × 1 × 2 × 1 − λ × 22 = 0, 2所以 λ2 + 2λ − 2 = 0,解得 λ = −1 ± 3. 3. 60∘【解析】因为直线 x + 3y + 2 = 0 的斜率为 − 13= − 3 ,故它的倾斜角为 150∘,3因为直线 x + 1 = 0 的斜率不存在,故它的倾斜角为 90∘,故直线 x + 3y + 2 = 0 与直线 x + 1 = 0 的夹角为 150∘ − 90∘ = 60∘.4. 6y ≥ 0,【解析】由约束条件 x − y + 1 ≥ 0, 得如图所示的三角形区域,x + y − 3 ≤ 0三个顶点坐标为 A 1,2 ,B −1,0 ,C 3,0 ,由 z = 2x + y 可得 y = −2x + z ,则 z 表示直线 y = −2x + z 在 y 轴上的截距,截距越大,z 越大,直线 z = 2x + y 过点 C 3,0 时,z 取得最大值为 6. 5. x − 1 2 + y − 2 2 =4【解析】所求圆的半径就是圆心 1,2 到直线 5x − 12y − 7 = 0 的距离:d = 所以圆的方程: x − 1 2 + y − 2 2 = 4. 5×1−12×2−7 52+ −12 2= 2,6. − 352x + my = 5, 1 0 3 0 1 1m = −1,故 y = 1 是方程组 nx − 3y = 2 的解,即 3n − 3 = 2, 解得: n = 5 ,3,A 32 = − 2 93所以 m = − 3.n57. 1,1 或 1 , 75 5【解析】x 2 + y 2 − 2mx − 4my + 6m − 2 = 0,所以 x 2 + y 2 − 2 = 2x + 4y − 6 m ,所以x 2 + y 2 − 2 = 0,2x + 4y − 6 = 0,解得 x = 1,y = 1 或 x = 1,y = 7.55所以定点的坐标是 1,1 或1 , 7 5 5.8. −1【解析】第 3 行第 2 列的元素的代数余子式x 4x4 4= −4 × 2x + 4 × 4x = −2x +2 1 − 2x . 所以 f x = −2x +2 1 − 2x ,y = 1 + f x= 1 − 2x +2 1 − 2x .令 y = 0,即 2x +2 1 − 2x = 1,解得:x = −1.9. 3, −2【解析】由题意,当 PA 取到最大值时,直线 PA 过圆心 2, −3 ,则直线 PA 的斜率为 1,直线方程为 y = x − 5,与圆的方程联立,可得 x − 2 2 + x − 2 2 = 2,所以 x = 3 或 1,根据题意,当 PA 取到最大值时,P 点的坐标为 3, −2 .10. 5: 1: 3【解析】记 △ ABC 的面积为 S ,因为 PA + 3PB + 5PC = 0,所以 − 1 PA = 3 PB + 5 PC = PD ,888则 D 在 BC 上,且 BD : CD = 5: 3,故 PD : AD = 1: 9,即当以 BC 为底时,△ BCP 的高是 △ ABC 的 1,9所以 S 2 = 1 S ,9同理:S 1 = 5 S ,S 3 = 1 S , 所以 S 1: S 2: S 3 = 5: 1: 3. 11. 1 − 2 2, 3【解析】在同一平面直角坐标系中画出曲线 y = 3 − 4x − x 2(注:该曲线是以点 C 2,3 为圆心、 2 为半径的圆不在直线 y = 3 上方的部分)与直线 y = x 的图象如图所示,2=2,b=1−22.2222平移该直线,结合图形分析可知,当直线沿y轴正方向平移到点0,3的过程中的任何位置,相应的直线与曲线y=3−4x−x2都有公共点;注意到与y=x平行且过点0,3的直线的方程是y=x+3;当直线y=x+b与以点C2,3为圆心、2为半径的圆(圆不在直线y=3上方的部分)相切时,有2−3+b结合图形可知,b的取值范围是1−22,3.12.23+2,4+42【解析】由题意:logax+logay=logaa4x4+logaa4y4,化简可得:logax−4logax+logay−4logay=8,令m=log a x,n=log a y,则有:n2+m2−4m−4n=8,且log a xy=n+m.因为a>1,x≥1,y≥1,所以n≥0,m≥0,因为n2+m2−4m−4n=8⇒n−22+m−22=42表示为2,2为圆心,半径为4的圆.令m+n=Z Z≥0,则n+m−Z=0.数形结合法:如图:当直线m+n−Z=0过B点或A点时最小.当直线m+n−Z=0过C点时最大.可知:A23+2,0,故得Z min=23+2,即为log a xymin=23+2.当过C点时,直线与圆相切,d=r=4=4−Z2,解得:Zmax=4+42,即为logaxymax=4+42.所以:logaxy的取值范围是23+2,4+42.第二部分22+32 .化简得: c − 1 = 7.即 c = −6 或 c = 8. sin θ = 0的两个不等的实根,得到 a + b = −tan θ −tan θ,sin θ ,所以直线 l AB : y = b + a x − a +b + a +b .x y 113. B 【解析】 3 5 1 = 5x − 2y + 9 + 10 − 3y − 3x = 0,整理得:2x − 5y + 19 = 0.−2 3 1由当 x = −2,y = 3 时,2x − 5y + 19 = −2 × 2 − 5 × 3 + 19 = 0,故 −2,3 在直线上,当 x = 4,y = 7 时,2x − 5y + 19 = 8 − 35 + 19 = 8 ≠ 0, 所以 4,7 不在直线上,当 x = 3,y = 5 时,2x − 5y + 19 = 6 − 25 + 19 = 0, 所以 3,5 在直线上,当 x = 0.5,y = 4 时,2x − 5y + 19 = 1 − 20 + 19 = 0, 所以 0.5,4 在直线上. 14. C 【解析】解法一:因为直线 2x + 3y − 6 = 0 关于点 1, −1 对称的直线斜率不变, 故设对称后的直线方程 l ʹ 为 2x + 3y + c = 0, 又因为点 1, −1 到两直线距离相等.所以 2−3+c 22+32= 2−3−6所以 l ʹ 方程为 2x + 3y − 6 = 0(舍)或2x + 3y + 8 = 0, 直线 2x + 3y − 6 = 0 关于点 1, −1 对称的直线方程是 2x + 3y + 8 = 0. 解法二:在直线 2x + 3y − 6 = 0 上任选两点,比如 A 0,2 ,B 3,0 , 所以点 A ,B 关于点 1, −1 对称的点 Aʹ,Bʹ 在所求直线上. 因为 A 与 Aʹ 的中点为点 1, −1 ,所以点 Aʹ 2, −4 ,同理可得 Bʹ −1, −2 . 由两点式得直线 AʹBʹ 方程为:2x + 3y + 8 = 0.15. A【解析】由已知得 CB ⋅ AC + AB = 0,即 BC 边的中线即为高,所以 AB = AC .16. B 【解析】由 a 和 b 为方程 x 2 + x 1 1ab = −1又 A a , a 2,B b , b 2 , 得到直线 AB 的斜率 k = a2−b 2a−b= a + b ,线段 AB 的中点坐标为a +b , a 2+b 2 2 2,2 22 2由圆 x 2 + y 2 = 1,得到圆心坐标为 0,0 ,半径 r = 1,则圆心到直线 AB 的距离a 2+b 2 − −3m −m = −m 2 − 3m = −m m + 3 ,= −m − 3,D y = 1 设 2t a + 7b ≠ −k ⋅ a + t b (k > 0),则 7 ≠ −kt , 得 t ≠ ± 14,d==a +b 2 2 2 12 + a + b 2a +b 2−2ab a +b 22 2 12 + a + b 2===1 = r .ab12 + a + b1 sin θ1 1+tan 2θ2所以直线 AB 与圆的位置关系是相切.第三部分17. 由题意得,D = m 1则 D x = −1 1 m −1 2m + 3 −m 3m 2m + 3= 2m 2 + 6m = 2m m + 3 ,(1)当 m ≠ 0 且 m ≠ −3 时,D ≠ 0,原方程组有唯一组解,所以 x =1 D × D x = m ,y =1 D× D y = −2,(2)当 m = 0 时,D = 0,D x = −3 ≠ 0,原方程组无解;(3)当 m = −3 时,D = 0,D x = 0,D y = 0,原方程组有无穷组解.综上,当 m = 0 时,无解;当 m = −3 时,无穷解;当 m ≠ 0 且 m ≠ −3 时,有唯一解,x = 1 , my = −2.18. 由题意可得 a ⋅ b = 2 × 1 × cos60∘ = 1,设向量 2t a + 7b 与向量 a + t b 的夹角为 θ,则 θ ∈ 90∘, 180∘ ,则有 cos θ < 0,且 cos θ ≠ −1.即 2t a + 7b 与向量 a + t b 的不能反向共线,且向量数量积 2t a + 7b ⋅ a + t b < 0,2t ≠ −k , 2由 2t a + 7b ⋅ a + t b < 0,得 2t a 2 + 7t b 2 + 2t 2 + 7 a ⋅ b < 0, 所以 2t 2 + 15t + 7 < 0,解得 −7 < t < − 1 且 t ≠ ±14, 22故实数 t 的取值范围为 t− 7 < t < − 1 , 且t ≠ −214 2.19. (1) 设直线 l 的方程为:y − 3 = k x − 1 k < 0 ,可得与坐标轴的交点分别为 A 0,3 − k ,B 1 − 3 , 0 .k所以第7页(共9页)−k ≥4+2−k−k=3+3=1.,2所以△PQR的外接圆C2的半径的平方=m+4k2,4k2=m2π1+k2>1,所以S2>mπ.13△??ABO=3−k1−2k19=−k++62−k19≥2−k×+62−k=6,当且仅当−k=3即k=−3时取等号.所以直线l与两坐标轴围成的图形的面积的最小值为6,此时直线l的方程为:y−3=−3x−1,化为3x+y−6=0.(2)由(Ⅰ)知直线l与两坐标轴截距之和=3−k+1−3=4+−k+k4+23,当且仅当−k=3即k=−3时取等号.所以直线l与两坐标轴截距之和的最小值为4+23,所以此时直线l的方程为:x+y1+33⋅320.(1)设AD中点为P x,y,由中点坐标公式可知,D点坐标为2x,2y−2,因为D点在圆x2+y2=16上,所以2x2+2y−22=16.故线段AD中点的轨迹方程为x2+y−12=4.(2)过点A且斜率为−3的直线方程为3x+4y−8=0,由(1)知,曲线E是以0,1为圆心,42为半径的圆,所以圆心到直线3x+4y−8=0的距离d=所以线段MN的长度为24−16=421.2554−832+42=4,521.(1)由题意,设tanα=k,则sinα=kk2+1所以△PQR的面积S1=2×1×因为0<k<1,1+k2kk2+1rm=k rm,k2+1所以0<S1<mr.(2)由题意得,PQ的垂直平分线方程为y=−1x,OR的垂直平分线方程为x=m,k2联立可得△PQR的外接圆C2的圆心坐标为m2,−m,2k24m2所以S2=π⋅m2+m21.4第8页(共9页)第9页(共9页)。
2016-2017学年上海市复旦⼤学附中⾼⼆(上)数学期中试卷带解析答案2016-2017学年上海市复旦⼤学附中⾼⼆(上)期中数学试卷⼀.填空题1.(3分)已知向量,.若,则实数k=.2.(3分)线性⽅程组的增⼴矩阵为.3.(3分)已知,则实数x的取值范围是.4.(3分)计算:=.5.(3分)若实数x,y满⾜,则z=x+y的最⼤值是.6.(3分)已知直线l经过点(3,2),且在两坐标轴上的截距相等,则直线l的⽅程是.7.(3分)直线l1与l2的斜率分别是⽅程6x2+x﹣1=0的两根,则直线l1与l2的夹⾓为.8.(3分)已知A(1,1)、B(﹣2,3),直线y=ax﹣1与线段AB相交,则实数a的范围是.9.(3分)直线l过点P(3,3),点Q(﹣1,1)到它的距离等于4,则直线l 的⽅程是.10.(3分)已知△ABC为等边三⾓形,AB=2,设点P,Q满⾜,,若,则λ=.11.(3分)直线2x+3y﹣6=0分别交x,y轴于A,B两点,点P在直线y=﹣x﹣1上,则|PA|+|PB|的最⼩值是.12.(3分)已知两个不相等的⾮零向量,,两组向量,,,,和,,,,均由2个和3个排列⽽成,记S=?+?+?+?+?,S min表⽰S所有可能取值中的最⼩值.则下列命题正确的是(写出所有正确命题的编号).①S有5个不同的值;②若⊥,则S min与||⽆关;③若∥,则S min与||⽆关;④若||>4||,则S min>0;⑤若||=2||,S min=8||2,则与的夹⾓为.⼆.选择题13.(3分)有下⾯四个命题:①若,则;②若a n>0,,则A>0;③若,则;④若,则;其中正确结论的个数是()A.1个 B.2个 C.3个 D.4个14.(3分)对于任意实数m,直线mx﹣y+1﹣3m=0必经过的定点坐标是()A.(3,1) B.(1,3) C.D.⽆法确定15.(3分)记,设a,b为平⾯内的⾮零向量,则()A.B.C.D.16.(3分)已知P1(a1,b1)与P2(a2,b2)是直线y=kx+1(k为常数)上两个。
2015-2016学年上海市复旦附中高二(下)期中数学试卷一、填空题(每题4分,共12题)1.(4分)复数+的虚部是.2.(4分)若两个球的表面积之比是1:4,则它们的体积之比是.3.(4分)已知平面α∥平面β,直线m⊊α,n⊊β,点A∈m,点B∈n,记点A,B之间的距离为a,点A到直线n的距离为b,直线m和n的距离c,则a,b,c的大小关系是.4.(4分)设A,B是平面α同侧的两点,点O∈α,OA,OB是平面α的斜线,射线OA,OB在α内的射线分别是射线OA′,OB′,若∠A′OB′=,则∠AOB 是(锐角、直角或钝角)5.(4分)在复平面内,到点﹣+3i的距离与到直线l:3z+3+2=0的距离相等的点的轨迹是.6.(4分)在正方体ABCD﹣A1B1C1D1中,M为棱A1B1的中点,则异面直线AM 与B1C所成的角的大小为(结果用反三角函数值表示).7.(4分)已知实数x和复数m满足(4+3i)x2+mx+4﹣3i=0,则|m|的最小值是.8.(4分)正四棱锥底面边长为4,侧棱长为3,则其体积为.9.(4分)在半径为10cm的球面上有A、B、C三点,如果AB=8,∠ACB=60°,则球心O到平面ABC的距离为cm.10.(4分)在地球表面上,地点A位于东经160°,北纬30°,地点B位于西经20°,南纬45°,则A、B两点的球面距离是(设地球的半径为R)11.(4分)在三棱锥P﹣ABC中,三条侧棱PA,PB,PC两两垂直,且PA=PB=3,PC=4,又M是底面ABC内一点,则M到三个侧面的距离的平方和的最小值是.12.(4分)小明在研究三棱锥的时候,发现下面一个真命题,在三棱锥A﹣BCD 中,已知∠BAC=α,∠CAD=β,∠DAB=γ(如图),设二面角B﹣AC﹣D的大小为θ,则cosθ=,其中f(γ)是一个与γ有关的代数式,请写出符合条件的f(γ)=.二、选择题(每小题5分,共12分)13.(5分)从正方体的八个顶点中任取四个点连线,在能构成的一对异面直线中,其所成的角的度数不可能是()A.30°B.45°C.60°D.90°14.(5分)对于复数z=a+bi(a、b∈R,i为虚数单位),定义‖z‖=|a|+|b|,给出下列命题:①对任何复数,都有‖z‖≥0,等号成立的充要条件是z=0;②‖z‖=‖‖;③‖z1‖=‖z2‖,则z1=±z2;④对任何复数z1,z2,z3,不等式‖z1﹣z3‖≤‖z1﹣z2‖+‖z2﹣z3‖恒成立,其中真命题的个数是()A.1B.2C.3D.415.(5分)下列四个命题:①任意两条直线都可以确定一个平面;②若两个平面有3个不同的公共点,则这两个平面重合;③直线a,b,c,若a与b共面,b与c共面,则a与c共面;④若直线l上有一点在平面α外,则l在平面α外.其中错误命题的个数是()A.1B.2C.3D.416.(5分)两个相同的正四棱锥底面重合组成一个八面体,可放于棱长为1的正方体中,重合的底面与正方体的某一个图平行,各顶点均在正方体的表面上(如图),该八面体的体积可能值有()A.1个B.2个C.3个D.无数个三、解答题(12分+12分+14分+14分)17.(12分)在复数范围内解方程:z2﹣4|z|+3=0.18.(12分)如图,AB是圆柱OO1的一条母线,已知BC过底面圆的圆心O,D 是圆O上不与点B、C重合的任意一点,AB=5,BC=5,CD=3.(1)求直线AC与平面ABD所成角的大小;(2)求点B到平面ACD的距离;(3)将四面体ABCD绕母线AB旋转一周,求由△ACD旋转而成的封闭几何体的体积.19.(14分)如图,在直四棱柱ABCD﹣A1B1C1D1中,AB∥CD,AA1=1,AB=3k,AD=4k,BC=5k,DC=6k(k>0);(1)求证:CD⊥平面ADD1A1(2)现将与四棱柱ABCD﹣A1B1C1D1形状和大小完全相同的两个四棱柱拼接成一个新的四棱柱,规定:若拼接成的新的四棱柱形状完全相同,则视为同一种拼接方案;问:共有几种不同的方案?在这些拼接成的新四棱柱中,记其中最小的表面积为f(k),写出f(k)的表达式(直接写出答案,不必说明理由).20.(14分)在四面体A﹣BCD中,有两条棱的长为a(a>0),其余棱的长度为1.(1)若a=,且AB=AC=,求二面角A﹣BC﹣D的余弦值;(2)求a的取值范围,使得这样的四面体是存在的.2015-2016学年上海市复旦附中高二(下)期中数学试卷参考答案与试题解析一、填空题(每题4分,共12题)1.(4分)复数+的虚部是.【考点】A5:复数的运算.【解答】解:复数+===.故其虚部为.故答案为.2.(4分)若两个球的表面积之比是1:4,则它们的体积之比是1:8.【考点】LG:球的体积和表面积.【解答】解:由已知两个球的表面积之比是1:4,所以两个球的半径之比是1:2,所以两个球的体积之比1:8;故答案为:1:8.3.(4分)已知平面α∥平面β,直线m⊊α,n⊊β,点A∈m,点B∈n,记点A,B之间的距离为a,点A到直线n的距离为b,直线m和n的距离c,则a,b,c的大小关系是c≤b≤a.【考点】LP:空间中直线与平面之间的位置关系.【解答】解:由于平面α∥平面β,直线m和n又分别是两平面的直线,则c即是平面之间的距离,即两个平面内直线的最短距离.而由于两直线不一定在同一平面内,则b一定大于c,判断a和b时,因为B是n上任意一点,则a大于b.故答案为:c≤b≤a.4.(4分)设A,B是平面α同侧的两点,点O∈α,OA,OB是平面α的斜线,射线OA,OB在α内的射线分别是射线OA′,OB′,若∠A′OB′=,则∠AOB 是锐角(锐角、直角或钝角)【考点】MI:直线与平面所成的角.【解答】解:在OA,OB上取点A,B,使得AB∥α,则射影长A′B′等于AB=c,设OA′=a,OB′=b,则a2+b2=c2,∴cos∠AOB=>=0,∴∠AOB是锐角;故答案为:锐角.5.(4分)在复平面内,到点﹣+3i的距离与到直线l:3z+3+2=0的距离相等的点的轨迹是y=3.【考点】A4:复数的代数表示法及其几何意义.【解答】解:设z=x+yi(x,y∈R),则直线l:3z+3+2=0化为:3x+1=0.∵点﹣+3i在直线3x+1=0上,∴在复平面内,到点﹣+3i的距离与到直线l:3z+3+2=0的距离相等的点的轨迹是y=3.故答案为:y=3.6.(4分)在正方体ABCD﹣A1B1C1D1中,M为棱A1B1的中点,则异面直线AM 与B1C所成的角的大小为arccos(结果用反三角函数值表示).【考点】LM:异面直线及其所成的角.【解答】解:以D为原点,DA为x轴,DC为y轴,DD1为z轴,建立空间直角坐标系,设正方体ABCD﹣A1B1C1D1棱长为2,则A(2,0,0),M(2,1,2),B1(2,2,2),C(0,2,0),=(0,1,2),=(﹣2,0,2),设异面直线AM与B1C所成的角为θ,cosθ===.∴θ=.∴异面直线AM与B1C所成的角为arccos.故答案为:.7.(4分)已知实数x和复数m满足(4+3i)x2+mx+4﹣3i=0,则|m|的最小值是8.【考点】A5:复数的运算.【解答】解:设m=a+bi,∵(4+3i)x2+(a+bi)x+4﹣3i=0,∴(4x2+ax+4)+(3x2+bx﹣3)i=0,∴,∴a=﹣,b=﹣,∴|m|==≥==8,当且仅当x2=1时“=”成立,故答案为:8.8.(4分)正四棱锥底面边长为4,侧棱长为3,则其体积为.【考点】LF:棱柱、棱锥、棱台的体积.【解答】解:如图,正四棱锥P﹣ABCD中,AB=4,PA=3,设正四棱锥的高为PO,连结AO,则AO=.在直角三角形POA中,.所以=.故答案为.9.(4分)在半径为10cm的球面上有A、B、C三点,如果AB=8,∠ACB=60°,则球心O到平面ABC的距离为6cm.【考点】MK:点、线、面间的距离计算.【解答】解:设A、B、C三点所在圆的半径为r,圆心为O′,则∵∠ACB=60°,∴∠AO′B=120°;则在等腰三角形ABO′中,AO′==8;即r=8;故球心O到平面ABC的距离为=6(cm);故答案为:6.10.(4分)在地球表面上,地点A位于东经160°,北纬30°,地点B位于西经20°,南纬45°,则A、B两点的球面距离是πR(设地球的半径为R)【考点】L*:球面距离及相关计算.【解答】解:由题意A,B在大圆上.∵地点A位于东经160°,北纬30°,地点B位于西经20°,南纬45°,∴纬度差为30°+180°﹣45°=165°=π,∵地球半径为R,∴A、B两地的球面距离是πR.故答案为:πR.11.(4分)在三棱锥P﹣ABC中,三条侧棱PA,PB,PC两两垂直,且PA=PB=3,PC=4,又M是底面ABC内一点,则M到三个侧面的距离的平方和的最小值是.【考点】MK:点、线、面间的距离计算.【解答】解:以P为原点,PA为x轴,PB为y轴,PC为z轴,建立空间直角坐标系,由已知得A(3,0,0),B(0,3,0),C(0,0,4),∴平面ABC为:=1,∴1=()2≤[()2+()2+()2](x2+y2+z2),解得x2+y2+z2≥.又M是底面ABC内一点,∴M到三棱锥三个侧面的距离的平方和的最小值是.故答案为:.12.(4分)小明在研究三棱锥的时候,发现下面一个真命题,在三棱锥A﹣BCD 中,已知∠BAC=α,∠CAD=β,∠DAB=γ(如图),设二面角B﹣AC﹣D的大小为θ,则co sθ=,其中f(γ)是一个与γ有关的代数式,请写出符合条件的f(γ)=cosγ.【考点】MJ:二面角的平面角及求法.【解答】解:如图,在平面ABC内,作CB⊥AC于C,在平面ACD内作CD⊥AC于C,连接BD,则∠BCD为二面角B﹣AC﹣D的平面角,大小为θ,设AB=a,AD=b,则BC=asinα,CD=bsinβ,BD2=a2+b2﹣2abcosγ,∴在△BCD中,cosθ==.在Rt△ACB中,AC=cosα,在Rt△ACD中,AC=bcosβ,∴a2cos2α=b2cos2β=AC2,∴a2cos2α+b2cos2β=2AC2=2abcosαcosβ,∴.∴f(γ)=cosγ.故答案为:cosγ.二、选择题(每小题5分,共12分)13.(5分)从正方体的八个顶点中任取四个点连线,在能构成的一对异面直线中,其所成的角的度数不可能是()A.30°B.45°C.60°D.90°【考点】MI:直线与平面所成的角.【解答】解:从正方体的八个顶点中任取四个点连线中,在能构成的一对异面直线中,其所成的角的度数可能有以下几种情况:①若两异面直线为CD和A1D1,此时两直线所成的角为90°..②若两异面直线为CD和AB1,此时两直线所成的角为45°.③若两异面直线为AC和DC1,此时两直线所成的角为60°.所以在能构成的一对异面直线中,其所成的角的度数不可能是30°.故选:A.14.(5分)对于复数z=a+bi(a、b∈R,i为虚数单位),定义‖z‖=|a|+|b|,给出下列命题:①对任何复数,都有‖z‖≥0,等号成立的充要条件是z=0;②‖z‖=‖‖;③‖z1‖=‖z2‖,则z1=±z2;④对任何复数z1,z2,z3,不等式‖z1﹣z3‖≤‖z1﹣z2‖+‖z2﹣z3‖恒成立,其中真命题的个数是()A.1B.2C.3D.4【考点】2K:命题的真假判断与应用.【解答】解:由复数z=a+bi(a、b∈R,i为虚数单位),定义‖z‖=|a|+|b|,知:在①中,对任何复数,都有‖z‖≥0,当z=0时,‖z‖=0;反之,当‖z‖=0时,z=0,∴等号成立的充要条件是z=0,故①成立;在②中,∵z=a+bi,=a﹣bi,∴‖z‖=‖‖=|a|+|b|,故②成立;在③中,当z1=2+3i,z2=3+2i时,‖z1‖=‖z2‖,但z1≠±z2,故③错误;④对任何复数z1,z2,z3,设z1=a1+b1i,z2=a2+b2i,z3=a3+b3i,则‖z1﹣z3‖=|a1﹣a3|+|b1﹣b3|,‖z1﹣z2‖+‖z2﹣z3‖=|a1﹣a2|+|a2﹣a3|+|b1﹣b2|+|b2﹣b3|,|a1﹣a3|≤|a1﹣a2|+|a2﹣a3|,|b1﹣b3|≤|b1﹣b2|+|b2﹣b3|,∴‖z1﹣z3‖≤‖z1﹣z2‖+‖z2﹣z3‖恒成立.故④成立.故选:C.15.(5分)下列四个命题:①任意两条直线都可以确定一个平面;②若两个平面有3个不同的公共点,则这两个平面重合;③直线a,b,c,若a与b共面,b与c共面,则a与c共面;④若直线l上有一点在平面α外,则l在平面α外.其中错误命题的个数是()A.1B.2C.3D.4【考点】LP:空间中直线与平面之间的位置关系.【解答】解:在①中,两条异面直线不能确定一个平面,故①错误;在②中,若两个平面有3个不共线的公共点,则这两个平面重合,若两个平面有3个共线的公共点,则这两个平面相交,故②错误;在③中,直线a,b,c,若a与b共面,b与c共面,则a与c不一定共面,如四面体S﹣ABC中,SA与AB共面,AB与BC共面,但SA与BC异面,故③错误;在④中,若直线l上有一点在平面α外,则由直线与平面的位置关系得l在平面α外,故④正确.故选:C.16.(5分)两个相同的正四棱锥底面重合组成一个八面体,可放于棱长为1的正方体中,重合的底面与正方体的某一个图平行,各顶点均在正方体的表面上(如图),该八面体的体积可能值有()A.1个B.2个C.3个D.无数个【考点】L@:组合几何体的面积、体积问题.【解答】解:设ABCD与正方体的截面四边形为A′B′C′D′,设AA′=x(0≤x≤1),则AB′=1﹣x,|AD|2=x2+(1﹣x)2=2(x﹣)2+故S ABCD=|AD|2∈[,1]V=S ABCD•h•2=S ABCD∈[,].∴该八面体的体积可能值有无数个,故选:D.三、解答题(12分+12分+14分+14分)17.(12分)在复数范围内解方程:z2﹣4|z|+3=0.【考点】A1:虚数单位i、复数;A8:复数的模.【解答】解:设z=x+yi (x、y∈R),则原方程变成(2分)⇔⇔或(4分)⇔或∴原方程的解为,±1,±3.(6分)18.(12分)如图,AB是圆柱OO1的一条母线,已知BC过底面圆的圆心O,D 是圆O上不与点B、C重合的任意一点,AB=5,BC=5,CD=3.(1)求直线AC与平面ABD所成角的大小;(2)求点B到平面ACD的距离;(3)将四面体ABCD绕母线AB旋转一周,求由△ACD旋转而成的封闭几何体的体积.【考点】LF:棱柱、棱锥、棱台的体积;MI:直线与平面所成的角;MK:点、线、面间的距离计算.【解答】解:(1)∵AB⊥平面BCD,CD⊂平面BCD,∴AB⊥CD,∵BC是圆O的直径,∴BD⊥CD,又BD⊂平面ABD,AB⊂平面ABD,AB∩BDE=B,∴CD⊥平面ABD.∴∠CAD是AC与平面ABD所成的角.∵AB=BC=5,∴AC=5,∴sin∠CAD==.∴直线AC与平面ABD所成角的大小为.(2)过B作BM⊥AD,垂足为M,由(1)得CD⊥平面ABD,CD⊂平面ACD,∴平面ABD⊥平面ACD,又平面ABD∩平面ACD=AD,BM⊂平面ABD,BM⊥AD,∴BM⊥平面ACD.∵BD==4,∴AD==.∴BM==.即B到平面ACD的距离为.(3)线段AC绕AB旋转一周所得几何体为以BC为底面半径,以AB为高的圆锥,线段AD绕AB旋转一周所得几何体为以BD为底面半径,以AB为高的圆锥,∴△ACD绕AB旋转一周而成的封闭几何体的体积V=﹣=15π.19.(14分)如图,在直四棱柱ABCD﹣A1B1C1D1中,AB∥CD,AA1=1,AB=3k,AD=4k,BC=5k,DC=6k(k>0);(1)求证:CD⊥平面ADD1A1(2)现将与四棱柱ABCD﹣A1B1C1D1形状和大小完全相同的两个四棱柱拼接成一个新的四棱柱,规定:若拼接成的新的四棱柱形状完全相同,则视为同一种拼接方案;问:共有几种不同的方案?在这些拼接成的新四棱柱中,记其中最小的表面积为f(k),写出f(k)的表达式(直接写出答案,不必说明理由).【考点】L2:棱柱的结构特征;LW:直线与平面垂直.【解答】(1)证明:取DC的中点E,连接BE,∵AB∥ED,AB=ED=3k,∴四边形ABED是平行四边形,∴BE∥AD,且BE=AD=4k,∴BE2+EC2=(4k)2+(3k)2=(5k)2=BC2,∴∠BEC=90°,∴BE⊥CD,又∵BE∥AD,∴CD⊥AD.∵侧棱AA1⊥底面ABCD,∴AA1⊥CD,∵AA1∩AD=A,∴CD⊥平面ADD1A1.(2)解:由题意可与左右平面ADD1A1,BCC1B1,上或下面ABCD,A1B1C1D1拼接得到方案新四棱柱共有此4种不同方案.写出每一方案下的表面积,通过比较即可得出f(k)=.20.(14分)在四面体A﹣BCD中,有两条棱的长为a(a>0),其余棱的长度为1.(1)若a=,且AB=AC=,求二面角A﹣BC﹣D的余弦值;(2)求a的取值范围,使得这样的四面体是存在的.【考点】L2:棱柱的结构特征;MJ:二面角的平面角及求法.【解答】解:(1)如图,过A作AE⊥BC,垂足为E,连接DE,则∠AED为二面角A﹣BC﹣D的平面角,在等边三角形BCD中,∵BC=CD=BD=1,∴DE=,在等腰三角形ABC中,∵AB=AC=,BC=1,∴AE=.在△AED中,由余弦定理得cos∠AED=;(2)当两条长为a的棱相交时,不妨设AB=AC=a,AD=BD=CD=BC=1,∵面ABC与平面BCD重合且A,D在BC异侧时,AE=,此时AB=AC=,面ABC与平面BCD重合且A,D在BC同侧时,AE=1+,此时AB=AC=.∴;当两条长为a的棱互为对棱时,不妨设BC=AD=a,AB=AC=BD=CD=1,BC,AD可以无限趋近于0,当ABCD为平面四边形时a=,∴0.综上,若四面体存在,则0<a.。
复旦附中高一期中数学卷一.填空题1.集合{1,2,3,,2015,2016}⋅⋅⋅的子集个数为________2.已知全集U =R ,集合{|1}A x x =≤,集合{|2}B x x =≥,则()U C A B =________3.已知集合{|12}A x x =≤≤,集合{|}B x x a =≤,若A B ⋂≠∅,则实数a 的取值范围是________4.如果全集{,,,,,}U a b c d e f =,{,,,}A a b c d =,{}A B a = ,(){}U C A B f = ,则B =________5.已知210a a >>,210b b >>,且12121a a b b +=+=,记1122A a b a b =+,1221B a b a b =+,12C =,则、、A B C按从小到大的顺序排列是________.6.已知Rt ABC ∆的周长为定值2,则它的面积最大值为__________.7.我们将b a -称为集合{|}M x a x b =≤≤的“长度”,若集合2{|}3M x m x m =≤≤+,{|0.5}N x n x n =-≤≤,且集合M 和集合N 都是集合{|01}x x ≤≤的子集,则集合M N ⋂的“长度”的最小值是________8.已知{}A x x =>,{|(3)(3)0}B x x x x =-+>,则A B = ________9.对任意两个集合X 与Y ,定义①{X Y x x X-=∈且}x Y ∉,②()()X Y X Y Y X∆=-- ,已知{}2,A y y x x R==∈,{}22B y y =-≤≤,则A B ∆=_________.10.已知常数a 是正整数,集合1{|||,}2A x x a a x Z =-<+∈,{|||2,}B x x a x Z =<∈,则集合A B ⋃中所有元素之和为________11.非空集合G 关于运算*满足:①对任意,a b G ∈,都有a b G *∈;②存在e G ∈使对一切a G ∈都有a e e a a *=*=,则称G 是关于运算*的融洽集,现有下列集合及运算:①G 是非负整数集,*运算:实数的加法;②G 是偶数集,*运算:实数的乘法;③G 是所有二次三项式组成的集合,*运算:多项式的乘法;④{|,}G x x a a b Q ==+∈,*运算:实数的乘法;其中为融洽集的是________12.集合(){},,R A x y y a x x ==∈,(){},,R B x y y x a x ==+∈,已知集合A B ⋂中有且仅有一个元素,则常数a 的取值范围是______________.二.选择题13.已知集合{1,2,3,,2015,2016}A =⋅⋅⋅,集合{|31,}B x x k k Z ==+∈,则A B ⋂中的最大元素是()A.2014B.2015C.2016D.以上答案都不对14.已知全集U =A B ⋃中有m 个元素,()()U U A B ⋃痧中有n 个元素.若A B ⋂非空,则A B ⋂的元素个数为A.mnB.m n+ C.n m- D.m n-15.命题“已知,x y R ∈,若220x y +=,则0x =且0y =”的逆否命题是()A.已知,x y R ∈,若220x y +≠,则0x ≠且0y ≠B.已知,x y R ∈,若220x y +≠,则0x ≠或0y ≠C.已知,x y R ∈,若0x ≠且0y ≠,则220x y +≠D.已知,x y R ∈,若0x ≠或0y ≠,则22x y +≠16.对任意实数,,a b c ,给出下列命题:①“a b =”是“ac bc =”的充要条件;②“5a +是无理数”是“a 是无理数”的充要条件;③“a b >”是“22a b >”的充分条件;④“4a <”是“3a <”的必要条件;其中真命题的个数是()A.1个B.2个C.3个D.4个三.解答题17.已知集合{1,2,3}A =,2{|(1)0,}B x x a x a x R =-++=∈,若A B A ⋃=,求实数a ;18.已知,,a b c R +∈,求证:3332222222()a b c ab a b bc b c ac a c ++≥+++++;19.设正有理数1a21211a a =++,求证:(11a 与2a 之间;(2)2a 比1a20.已知对任意实数x ,不等式2(3)10mx m x --+>成立或不等式0mx >成立,求实数m 的取值范围;21.已知关于x 的不等式2(4129)(211)0kx k k x ---->,其中R k ∈;(1)试求不等式的解集A ;(2)对于不等式的解集A ,记B A Z = (其中Z 为整数集),若集合B 为有限集,求实数k 的取值范围,使得集合B中元素个数最少,并用列举法表示集合B;复旦附中高一期中数学卷一.填空题1.集合{1,2,3,,2015,2016}⋅⋅⋅的子集个数为________【答案】20162【分析】若集合中有n 个元素,则该集合有2n 个子集,显然,集合中的元素有2016个,即2016n =,代入2n 中即可【详解】由题,集合中有2016个元素,所以该集合有20162个子集,故答案为:20162【点睛】本题考查集合的子集个数,属于基础题2.已知全集U =R ,集合{|1}A x x =≤,集合{|2}B x x =≥,则()U C A B = ________【答案】{|12}x x <<【分析】先求的A B ⋃,再求得补集即可【详解】由题,{|1A B x x ⋃=≤或}2x ≥,所以(){}U |12A B x x ⋃=<<ð,故答案为:{|12}x x <<【点睛】本题考查集合的并集、补集运算,属于基础题3.已知集合{|12}A x x =≤≤,集合{|}B x x a =≤,若A B ⋂≠∅,则实数a 的取值范围是________【答案】1a ≥【分析】由A B ⋂≠∅,画出数轴,表示出集合,即可求解【详解】因为A B ⋂≠∅,则画出数轴,并表示出集合,如下:可得1a ≥,故答案为:1a ≥【点睛】本题考查已知交集结果求参数范围,属于基础题4.如果全集{,,,,,}U a b c d e f =,{,,,}A a b c d =,{}A B a = ,(){}U C A B f = ,则B =________【答案】{,}a e 【分析】由题,用维恩图来表示集合,由图即可得到B 集合【详解】由题,将集合用维恩图表示,则{},B a e =,故答案为:{,}a e 【点睛】本题考查图示法处理集合问题,属于基础题5.已知210a a >>,210b b >>,且12121a a b b +=+=,记1122A a b a b =+,1221B a b a b =+,12C =,则、、A B C 按从小到大的顺序排列是________.【答案】B <C <A【分析】根据题设,取符合题设的特殊值即可快速判断,或者采用排序原理也可判断.【详解】方法一:212112120,0,1a a b b a a b b >>>>+=+= ,不妨令12121212,,,3333a ab b ====,11221221145224,999999A a b a bB a b a b =+=+==+=+=,1 4.529C == ,B C A \<<,故答案为:B <C <A .方法二:∵210a a >>,210b b >>,∴由排序原理可知:22112112a b a b a b a b +>+,∵12121,1a a b b +=+=,()()1212111221221a a b b a b a b a b a b ∴=++=+++()()()2211211222112a b a b a b a b a b a b =+++<+221112a b a b ∴+>,∴A >C >B ﹒故答案为:B <C <A .6.已知Rt ABC ∆的周长为定值2,则它的面积最大值为__________.【答案】3-.【分析】设出三角形的边长,根据周长和勾股定理列方程组,利用基本不等式求得ab 的最大值,进而求得三角形面积的最大值.【详解】设Rt ABC ∆三条边长分别为,,a b c ,其中c 为斜边长,所以2222a b c c a b++=⎧⎨=+⎩,2a b +=,2≥,2≤=-,所以6ab ≤-则三角形的面积132ABC S ab ∆=≤-.故答案为3-.【点睛】本小题主要考查利用基本不等式求三角形面积的最大值,考查直角三角形的性质,考查化归与转化的数学思想方法,属于中档题.7.我们将b a -称为集合{|}M x a x b =≤≤的“长度”,若集合2{|}3M x m x m =≤≤+,{|0.5}N x n x n =-≤≤,且集合M 和集合N 都是集合{|01}x x ≤≤的子集,则集合M N ⋂的“长度”的最小值是________【答案】16【分析】当集合M N ⋂的“长度”的最小值时,M 与N 应分别在区间[]0,1的左右两端,由此能求出M N ⋂的“长度”的最小值【详解】由题,M 的“长度”为23,N 的“长度”为12,当集合M N ⋂的“长度”的最小值时,M 与N 应分别在区间[]0,1的左右两端,故M N ⋂的“长度”的最小值是2111326+-=,故答案为:16【点睛】本题考查交集的“长度”的最小值的求法,考查新定义的合理运用8.已知{}A x x =>,{|(3)(3)0}B x x x x =-+>,则A B = ________【答案】{|30}-<<x x【分析】先分别求解集合中元素的所满足的不等式,再由交集的定义求解即可【详解】由题,因为20xx >-≥⎪⎩,解得1x <,则{}|1A x x =<,因为()()330x x x -+>,解得30x -<<或3x >,则{|30B x x =-<<或}3x >,所以{}|30A B x x ⋂=-<<,故答案为:{|30}-<<x x 【点睛】本题考查集合的交集运算,考查含根式的不等式的运算,考查解高次不等式9.对任意两个集合X 与Y ,定义①{X Y x x X -=∈且}x Y ∉,②()()X Y X Y Y X ∆=-- ,已知{}2,A y y x x R ==∈,{}22B y y =-≤≤,则A B ∆=_________.【答案】[)()2,02-+∞ ,【分析】由A ={y |y =x 2,x ∈R }={y |y ≥0},B ={y |﹣2≤y ≤2},先求出A ﹣B ={y |y >2},B ﹣A ={y |﹣2≤y <0},再求A △B 的值.【详解】∵A ={y |y =x 2,x ∈R }={y |y ≥0},B ={y |﹣2≤y ≤2},∴A ﹣B ={y |y >2},B ﹣A ={y |﹣2≤y <0},∴A △B ={y |y >2}∪{y |﹣2≤y <0},故答案为[﹣2,0)∪(2,+∞).【点睛】本题考查集合的交、并、补集的运算,解题时要认真审题,仔细解答,注意正确理解X ﹣Y ={x |x ∈X 且x ∉Y }、X △Y =(X ﹣Y )∪(Y ﹣X ).10.已知常数a 是正整数,集合1{|||,}2A x x a a x Z =-<+∈,{|||2,}B x x a x Z =<∈,则集合A B ⋃中所有元素之和为________【答案】2a【分析】分别求出集合A 、B 中的元素,再求出集合A 、B 的并集,即可求解【详解】由题,因为12x a a -<+,所以11222x a -<<+,则11|2,22A x x a x Z ⎧⎫=-<<+∈⎨⎬⎩⎭;因为2x a <,所以22a x a -<<,则{}|22,B x a x a x Z =-<<∈,因为常数a 是正整数,所以{}0,,,,2A a a = ,{}21,,0,,21B a a =-+- ,所以{}21,,0,,21,2A B a a a ⋃=-+- ,所以A B ⋃中所有元素之和是2a ,故答案为:2a【点睛】本题考查集合的并集,考查解含绝对值的不等式11.非空集合G 关于运算*满足:①对任意,a b G ∈,都有a b G *∈;②存在e G ∈使对一切a G ∈都有a e e a a *=*=,则称G 是关于运算*的融洽集,现有下列集合及运算:①G 是非负整数集,*运算:实数的加法;②G 是偶数集,*运算:实数的乘法;③G 是所有二次三项式组成的集合,*运算:多项式的乘法;④{|,}G x x a a b Q ==+∈,*运算:实数的乘法;其中为融洽集的是________【答案】①④【分析】逐一验证几个选项是否分别满足“融洽集”的两个条件,若两个条件都满足,是“融洽集”,有一个不满足,则不是“融洽集”【详解】①对于任意非负整数,a b ,则a b +仍为非负整数,即a b G +∈;取0e =,则00a a a +=+=,故①符合题意;②对于任意偶数,a b ,则ab 仍为偶数,即ab G ∈;但是不存在e G ∈,使对一切a G ∈都有ae ea a ==,故②不符合题意;③对于G 是所有二次三项式组成的集合,若,a b G ∈,ab 不再是二次三项式,故③不符合题意;④对于{|,}G x x a a b Q ==+∈,设1x a =+2x c =+,则()(122x x ac bd ad bc ⋅=+++,即12x x G ⋅∈;取1e =,则11a a a ⨯=⨯=,故④符合题意,故答案为:①④【点睛】本题考查对新定义“融洽集”的理解,考查理解分析能力12.集合(){},,R A x y y a x x ==∈,(){},,R B x y y x a x ==+∈,已知集合A B ⋂中有且仅有一个元素,则常数a 的取值范围是______________.【答案】[]1,1-【分析】将A B ⋂中有且仅有一个元素,转化为方程只有一个解,分情况讨论,确定参数范围.【详解】由集合(){},,R A x y y a x x ==∈,(){},,R B x y y x a x ==+∈,且A B ⋂中有且仅有一个元素,a x x a ∴=+只有1个解,若0x ≥,则ax x a =+,1a x a =-,若0x <,则ax x a -=+,1ax a =-+,所以0101a a a a ⎧≥⎪⎪-⎨⎪-≥⎪+⎩或0101aa a a ⎧≤⎪⎪-⎨⎪-≤⎪+⎩或101a a a =⎧⎪⎨-<⎪+⎩或011a a a ⎧≥⎪-⎨⎪=-⎩,解得11a -≤≤,故答案为:[]1,1-.二.选择题13.已知集合{1,2,3,,2015,2016}A =⋅⋅⋅,集合{|31,}B x x k k Z ==+∈,则A B ⋂中的最大元素是()A.2014B.2015C.2016D.以上答案都不对【答案】A【分析】由题意可知集合B 表示整数的3倍且大1的数的集合,则找到集合A 中符合条件的最大元素即可【详解】由题,因为{|31,}B x x k k Z ==+∈,即为整数的3倍且大1的数的集合,则A B ⋂中的最大元素为2014,故选:A【点睛】本题考查集合的交集定义,属于基础题14.已知全集U =A B ⋃中有m 个元素,()()U U A B ⋃痧中有n 个元素.若A B ⋂非空,则A B ⋂的元素个数为A.mnB.m n+ C.n m- D.m n-【答案】D【详解】因为()()()U UUB A B A ⋃=⋂痧所以()()U UU A B A B ⋂=⋃⎡⎤⎣⎦痧,所以A B ⋂共有m n -个元素,故选D .15.命题“已知,x y R ∈,若220x y +=,则0x =且0y =”的逆否命题是()A.已知,x y R ∈,若220x y +≠,则0x ≠且0y ≠B.已知,x y R ∈,若220x y +≠,则0x ≠或0y ≠C.已知,x y R ∈,若0x ≠且0y ≠,则220x y +≠D.已知,x y R ∈,若0x ≠或0y ≠,则22x y +≠【答案】D【分析】直接利用逆否命题的定义得到答案.【详解】己知,x y R ∈,若220x y +=,则0x =且0y =”的逆否命题是:己知,x y R ∈,若0x ≠或0y ≠,则220x y +≠故选D【点睛】本题考查了命题的逆否命题,意在考查学生对于命题基础知识的掌握情况.16.对任意实数,,a b c ,给出下列命题:①“a b =”是“ac bc =”的充要条件;②“5a +是无理数”是“a 是无理数”的充要条件;③“a b >”是“22a b >”的充分条件;④“4a <”是“3a <”的必要条件;其中真命题的个数是()A.1个B.2个C.3个D.4个【答案】B【分析】利用等式与不等式的性质逐一验证命题的真假即可【详解】①“a b =”⇒“ac bc =”,但当0c =时,“ac bc =”无法推出“a b =”,则“a b =”是“ac bc =”的充分不必要条件,故①是假命题;②“5a +是无理数”⇒“a 是无理数”,且“a 是无理数”⇒“5a +是无理数”,则“5a +是无理数”是“a 是无理数”的充要条件,故②是真命题;③当12a b =>-=时,2214a b =<=,即“a b >”无法推出“22a b >”,且当2241a b =>=时,21a b =-<=,即“22a b >”无法推出“a b >”,则“a b >”是“22a b >”的既不充分也不必要条件,故③是假命题;④因为{}|3a a <{}|4a a <,所以“4a <”是“3a <”的必要条件,故④是真命题;综上,真命题有2个,故选:B【点睛】本题考查命题的真假的判断,考查两命题的充分性和必要性的判断,考查等式与不等式的性质的应用三.解答题17.已知集合{1,2,3}A =,2{|(1)0,}B x x a x a x R =-++=∈,若A B A ⋃=,求实数a ;【答案】1a =或2或3【分析】由A B A ⋃=可得B A ⊆,分别讨论B =∅与B ≠∅的情况,进而求解即可【详解】由A B A ⋃=可得B A ⊆,若B =∅,则()2140a a ∆=+-<,解得a ∈∅;若B ≠∅,则()()10x a x --=,解得1x a =,21x =,①当1a =,则{}1B =,符合题意;②当2a =,则{}1,2B =,符合题意;③当3a =,则{}1,3B =,符合题意;综上,1a =或2或3【点睛】本题考查已知集合的包含关系求参数,考查分类讨论思想18.已知,,a b c R +∈,求证:3332222222()a b c ab a b bc b c ac a c ++≥+++++;【答案】证明见解析【分析】先对33+a b 与22a b ab +作差证明3322a b a b ab +≥+,同理证明3322a c a c ac +≥+,3322b c b c bc +≥+,再求和即可得证【详解】证明:()()()()()()()()233222222a b a b ab a a b b b a a b a b a b a b +-+=-+-=--=+-,因为,,a b c R +∈,所以0a b +>,()20a b -≥,所以()()33220a b a b ab +-+≥,即3322a b a b ab +≥+,同理,3322a c a c ac +≥+,3322b c b c bc +≥+,所以333333222222a b b c a c a b ab b c bc a c ac +++++≥+++++,即3332222222()a b c ab a b bc b c ac a c++≥+++++【点睛】本题考查作差法证明不等式,考查推理论证能力19.设正有理数1a21211a a =++,求证:(11a 与2a 之间;(2)2a 比1a【答案】(1)证明见解析(2)证明见解析【分析】(1)作差(12111a a a -=+,讨论1a2a (2)整理问题为21a a <-,进而求证即可【详解】证明:(1)(121112111a a a a --=+-++,因为若1a >,则10a >,又10<,则2a <;若1a <则10a <,又10-<,则2a >,介于1a 与2a 之间(2)12111121a a a a a a ----=--+,因为10a >20-<,10a>,所以210a a -<,所以21a a -<-所以2a 比1a 【点睛】本题考查不等式的证明,考查运算能力与分类讨论思想20.已知对任意实数x ,不等式2(3)10mx m x --+>成立或不等式0mx >成立,求实数m 的取值范围;【答案】19m <<【分析】①对任意实数x ,不等式2(3)10mx m x --+>成立,讨论0m =与0m ≠的情况,进而求解;②对任意实数x ,不等式0mx >成立,则m ∈∅,二者求并集即可【详解】解:①由题,对任意实数x ,不等式2(3)10mx m x --+>成立,当0m =时,不等式为310x -+>不成立,舍去;当0m ≠时,()20340m m m >⎧⎪⎨∆=--<⎪⎩,解得19m <<;②对任意实数x ,不等式0mx >成立,则m ∈∅,综上,19m <<【点睛】本题考查含参的一元二次不等式恒成立问题,考查分类讨论思想21.已知关于x 的不等式2(4129)(211)0kx k k x ---->,其中R k ∈;(1)试求不等式的解集A ;(2)对于不等式的解集A ,记B A Z = (其中Z 为整数集),若集合B 为有限集,求实数k 的取值范围,使得集合B 中元素个数最少,并用列举法表示集合B ;【答案】(1)答案见解析(2)[44k ∈--+,{2,3,4,5}B =【分析】(1)对k 进行分类讨论,分别讨论0k =,0k <,01k <<或9k >,19k ≤≤的情况,进而求解即可;(2)由(1)可知当0k <时,集合B 为有限集,利用对勾函数可知933442k k ++≤,当且仅当3k =-时等号成立,进而求解即可【详解】(1)当0k =,11{|}2A x x =<;当0k ≠时,令21291142k k k ++=,解得1k =或9k =,则当1k <或9k >时,9113442k k ++<,当19k <<时,9113442k k ++>,①当0k <,911{|3}442k A x x k =++<<;②当01k <<或9k >,11{|2A x x =<或93}44k x k >++;③当19k ≤≤,9{|344k A x x k =<++或11}2x >;(2)因为B A Z = (其中Z 为整数集),由(1),当0k ≥时,集合B 中的元素的个数无限;当0k <时,集合B 中的元素的个数有限,此时集合B 为有限集,因为0k <,所以9933333444422k k k k ⎛⎫++=---+≤-+= ⎪⎝⎭,当且仅当944k k -=-,即3k =-时等号成立,所以{2,3,4,5}B =且93144k k++≥,所以2890k k ++≤,所以[44k ∈--+【点睛】本题考查解含参的不等式,考查交集的定义的应用,考查分类讨论思想。
2017学年复旦附中第一学期期中考试试卷初一年级数学(满分100 时间:90分钟)一、选择题:(本大题共6题,每题2分,满分12分)1.下列代数式a xy x x x ,4,1,2,3732--中单项式的个数是 ( ) A.1个 B.2个 C.3个 D.4个2.下列运算正确的是( )A. 32)(aB.4223432y y =⎪⎭⎫ ⎝⎛- C.236a a a =÷ D.532a a a =⋅ 3.下列各式从左到右各式是因式分解的是( )A. 1)1)(1(2-=-+x x xB.6)5(652+-=+-x x x xC.22)1(12-=+-x x xD.)()(y x b y x a by bx ay ax +++=+++4.下列分式化简正确的是( ) A. b a b a b a -=--3)(32 B.32322a a a a =- C.b a b ab a 31236142+=-- D.ba b a b a +=++122 5.数学老师上课出了一道因式分解的思考题,题意是1622++mx x 能在有理数的范围内因式分解,则整数m 的值有几个,小军和小华为此争论不休,请你判断整数m 的值有几个?( ) A.4个 B.5个 C. 6个 D.8个6.从边长为a 的大正方形纸板中挖去一个边长为b 的小正方形后,将其裁成四个相同的等腰梯形(图甲),然后拼成一个平行四边形(图乙),那么通过计算两个图形的阴影部分的面积,可以验证成立的公式是( )A. 222)(b a b a -=-B.))((22b a b a b a +-=-C.2222)(b ab a b a +-=-D.b ab a b a ++=+2)(2二、填空题:(本大题共12题,每题3分,满分36分)7.“12减去y 的41的差”用代数式表示是: 8.将多项式153322---y y x xy 按字母y 升幂排列是: 9.使分式25-+x x 有意义的条件是: 10.计算:=÷-22332)453(y xy y 11.计算:=+--+-21212a a a a 12.若,3293211⨯=⨯⨯m 则=m13.如果,4,5==+ab b a 则=-b a14.要使)12)(3(22---x x x ax 的展开式中不含2x ,则=a 15.c b a ,,为三角形三边长,022=--+bc b ac a ,则该三角形的形状为16.现在规定一种运算ab b b a --=2*,期中ab 为有理数,=-m n m *)(17.李丽从家到学校的路程为S 米,无风时她以平均a 米/秒的速度骑行,便能按时到达;当风速为b 米/秒时,她若顶风按时到校,请用代数式表示她必须提前出发的时间是18.在图中取阴影等边三角形各边的中点,连成一个等边三角形,将其挖去,得到图;对图中的每个阴影等边三角形仿照先前的做法,得到图,如此继续.如果图的等边三角形面积为,则第个图形中所有阴影三角形面积的和为_________.三、简答题:(本大题共7小题,每小题4分,满分28分)19.计算:ax by axy b by ax 41)2(2)221(22÷⎥⎦⎤⎢⎣⎡-+- 20.计算:)52)(52(++-+-+z y x z y x21.解方程:2229)31)(13()12()3(4x x x x x +-+=+--22.因式分解:222222)53()35(n m n m +-+23.因式分解:72)(18)(222+---x x x x24.因式分解:ab b a 4)1)(1(22--- 25.先化简,再求值:11)1112(22+÷+-+-x x x x x ,期中.2-=x 四、解答题(本大题共5小题,第26-29题每题5分,第30题4分,满分24分)26.已知311=-y x ,求yxy x y xy x ---+2535的值。
复旦大学附属中学2016学年第一学期高二年级期中考试试卷2016-11-8II. Grammar and vocabulary (26%)Section ADirections: Read the following two passages. Fill in the blanks to make the passage coherent. For the blanks with a given word, fill in each blank with the proper from of the given word. For the other blanks, fill in each blank with one proper word. Make sure that your answers are grammatically correct.(A)As a student, I get so many assignments every day. I have to stay up late in order to finish all my homework. I used to complain about all this pressure (25) ______ school with my classmates. We did not appreciate our teachers for their hard work. We only (26) _______ (know) that we got a lot of homework.After a few months, we did not complain about homework anymore (27) _______ we knew that our teachers worked (28) ________ (hard) than we did. We had no right to complain. Sometimes, we said, “I didn’t go to bed until 12:00 o’clock last night. Now I just want to sleep.” Our teacher would answer us, “I go to bed at 1:00 a.m. every day.” Since we knew how hard teachers work, we started to appreciate them. To give our thanks, we wrote a big card to the teachers (29) _______ it was teachers’ day. When they got our card, they (30) _________ (touch) because their students finally knew the teachers’ effort.After (31) _________ (give) the card, I realized (31) powerful the sentence “thank you” is. When we give our thanks to somebody, the world is full of love.I say “thank you” to my friends, fami ly, classmates, teachers, and even strangers.I like to see the smiles on their faces, so (32) ________ (say) “thank you” every day is the way I make the world a better place.(B)Phyllis Rawlins’ house was destroyed after a tornado(龙卷风) swept through her town of Kokomo, Ind., on Sunday. Last summer, she lost (33)_______ husband of over 40 years, Edgar. In the tornado’s rubble(瓦砾), Rawlins searched for Edgar’s wedding ring. “Digging and praying. Digging and praying,” she told local station Fox 59.“It was everything to me, because that’s one thing that I had,” she said.Rawlins had been visiting family in Kentucky when the storm came through. She returned (34) ________ find her home completely in pieces. “This was the house that love built,” she told W THR.Without her husband or her house, she was determined to find the ring. But (35) ________ (locate) it among the piles of rubble seemed to be hopeless.Somehow, her brother spotted something under (36) _______ piece of the roof and called her over. The ring, (37) _______ (bury) in the rubble, had turned up.“It was a miracle,” Rawlins said. “We both just hugged each other, (38) _______ (cry). That was (39) _______ I had searched and searched for,”When all was lost, the special ring he left was finally found.“I’m very strong with my faith, and I know that God is in control of (40) _________, the good and the bad,” Rawlins said.Section BDirections: Complete the following passage by using the words in the box.Each word can only be used once. Note that there is one word more than you need.Zhou Yeling couldn’t wait until 7am for a long-awaited date with her favourite Englishman.The 19-year-old from the city of Shanghai dragged herself out of bed at 5am to watch the third season premiere of Sherlock on the BBC’s website. Two hours later, the episode started showing with Chinese subtitles on , a video website.Youku says it was viewed more than 5 million times in the first 24 hours, becoming the site’s most popular programme to 41.“I was excited beyond words,” said Zhou, a student in the central Chinese city of Changsha.Sherlock has become a global 42, but nowhere more than in China, which was one of the first countries where the new season was shown.Online fan clubs have attracted thousands of members. Chinese fans write their own stories about the modern version of author Arthur Conan Doyle’s prickly, Victorian detective and his 43, Dr Watson, to fill the time between the brief, three-episode seasons.“The Sherlock production team shoot something more like a movie, not just a TV drama,” said YuFei, a veteran writer of TV crime dramas for Chinese television. Scenes in which Holmes44 clues in a suspect’s clothes or picks apart an alibi are so richly detailed that “it seems like a wasteful luxury,” Yu said.Even the Communist Party newspaper People’s Daily is a fan.“45 plot, bizarre story, exquisite production, excellent performances,” it said of the third season’s first episode.With its mix of odd villains, eccentric aristocrats and fashionable London settings, Sherlock can draw on a Chinese fondness for a storybook version of Britain. Wealthy Chinese send their children to local branches of British schools such as Eton and Dulwich.On the outskirts of Shanghai, a developer has built Thames Town, modelled on an English village with 46Tudor houses and classic red phone booths.“The whole drama has the rich scent of British culture and47,” Yu said. “Our drama doesn’t have that.”The series has given a48to , part of a fast-growing Chinese online video industry. Dozens of sites, some independent and others run by Chinese television stations, show local and imported programmes such as The Good Wife and The Big Bang Theory. says that after two weeks, total 49 for the Sherlock third season premiere had risen to 14.5 million people. That compares with the 8 to 9 million people who the BBC says watch first-run episodes in Britain. The total in China is bumped up by viewers on pay TV service BesTV, which also has rights to the programme.Appearing online gives Sherlock an unusual 50over Chinese dramas. To support a fledgling industry, communist authorities have exempted video websites from most censorship and limits on showing foreign programming that apply to traditional TV stations. That allows outlets such as Youku to show series that might be deemed too violent or political for state TV and to release them faster.III. Cloze (15points)Section A (15分)Directions: For each blank in the following passage there are four words or phrases marked A, B, C and D. Fill in each blank with the word or phrase that best fits the context.Summer is an ideal time to get the jump on your college admissions essay. These less hurried months before the onslaught of a highly pressured fall offer the chance for students to think, 51and connect with a writing topic of your admissions essay.So how can you use the summer to your best 52?First,you’d better clear your head. 53 like TV, texting, video games and Internet surfing can seriously inhibit 54. Once your school term is over, 55some time away from those electronic diversions and find a park bench, rooftop, library carrel or some other quiet place where you can hear your thoughts bubbling up from deep down in your 56Next,ask yourself questions. In looking for an essay topic, an excellent way to begin is by asking questions that can 57some juicy conflict. But don’t forget write it down. carry around a pad and pencil or some kind of wireless 58to record your thoughts. if you don’t write it down, you’re 59 to lose them.Certainly,you are required to familiarize yourself with the narrative form. It is far better to think of the college admissions essay as your chance to tell a good story. Stories are narratives. Be conscious of their narrative 60Last but not least.you should enjoy yourself. These feel-good months make it easier to relax, and61the college admissions essay with less anxiety is a good thing. It would be extremely 62to view this assignment as a creative act. You’ll want to 63yourself to the work, think that your essay will 64 through a series of drafts and allow yourself to take some 65in the process.51. A. renew B. reflect C. reserve D. resign52. A.advantage B.gain C favor D. profit53. A.Discussions B. Distributions C. Distinctions D. Distractions54. A.motive B. awareness C.inspiration D.shelter55. A.schedule B. program C. draft D. enclose56. A. consequence B.consensus C. conscience D. consciousness.57. A. turn B. dress C.catch D. run58. A. dignity B.devil C. dialect D.device59. A. free B. bound C. obliged D.possible60. A. technologies B.negotiations C.discussions D. techniques61. A. moving B.accessing C.approaching D. entering62. A. Irresistible B. beneficial C.discreet D.inevitable63. A.attach B.reply C. commit D. appeal64. A.emerge B.flutter C.stoop D. evolve65. A. pleasure B. worth C.literacy D. courageIV. Reading Comprehension (15 points)Section ADirections:Read the following three passages. Each passage is followed by several questions or unfinished statements. For each of them there are four choices marked A,B,C,andD.choose the one that fits best according to the information given in the passage you have read.(A)Texting has long been bemoaned (哀叹)as the downfall of the written word,“penmanship for illiter,”as one critic called it. To which the proper response is LOL.Texting properly isn′t writing at all. It′s a “spoken” language that is getting richer and more complex by the year.First,some historical perspective. Writing was only invented 5,500 years ago. whereas Ianguage probably traces back at least 80.000 years. Thus talking came first; writing is just a craft that came along later. As such, the first writing was based on the way people talk,with short sentences.However, while talking is largely subconscious and rapid, writing is deliberate and slow, Over time,writers took advantage of this and started cratting long-winded sentences such as this one:The whole engagement lasted above 12 hours, till the gradual retreat of the Per trsians was changed into a disorderly flight, of which the shameful example was given by the principal leaders and……”No one talks like that casually — or should. But it is natural to desire to do so for special occasions. In the old days, we didn’t much wr ite like talking because there was no mechanism to reproduce the speed of conversation. But texting and instant messaging do —and a revolution has begun. It involves the crude mechanics of writing, but in its economy, spontaneity and even vulgaritv. texting is actually a new kind of talking, with its own kind of grammar and conventions.Take LOL. It doesn’t actually mean “laughing out loud” in a literal sense anymore. LOL has evolved into something much subtler and sophisticated and is used even when not hing is remotely amusing. Jocelyn texts “Where have you been?” and Annabelle texts back ,LOL at the library studying for two hours.” LOL signals basic empath)’(同感)between tcxters. easing tension and creating a sense of equality. Instead of having a literal meaning, it docs something - conveying an attitude —just like the -cd ending conveys past tense rather than “meaning.,anything. LOL.of all things, is grammar.Of course no one thinks about that consciously. But then most of communication operates without being noticed. Over time, the meaning of a word or an expression drifts meat used to mean any kind of food, silly used to mean, believe it or not,blessed.Civilization, then,is fine 一 people banging away on their smartphones are fluently using a code separate from the one they use in actual writing, and there is no evidence that texting is ruining composition skills. Worldwide people speak differently from the w ay they write, and texting -quick, casual and only intended to be read once — is actually a way of talking with your fingers.66.In what way does the author say writing is different from talking?A) It is crafted with specific skills.B) It expresses ideas more deeply.C) It does not have as long a history.D) It is not as easy to comprehend.67.Why is LOL much used in texting?A) It brings texters closer to each other.B) It shows the texter's sophistication.C) It is a trendy way to communicateD) It adds to the humor of the text68.Examples like meat and silly are cited to showA) the difference between writing and talkingB) how different words are used in textingC) why people use the words the way they doD) the gradual change of word meaning(B)Mark Twain has been called the inventor of the American novel. And he surely deserves additional praise: the man who popularized the clever literary attack on racism.I say clever because anti-slavery fiction had been the important part of the literature in the years before the Civil War. H. B. Stowe’s Uncle Tom’s Cabin is only the most famous example. These early stories dealt directly with slavery. With minor exceptions, Twain planted his attacks on slavery and prejudice into tales that were on the surface about something else entirely. He drew his readers into the argument by drawing them into the story.Again and again, in the postwar years, Twain seemed forced to deal with the challenge of race. Consider the most controversial, at least today, of Twain’s novels, Adventures of Huckleberry Finn. Only a few books have been kicked off the shelves as o ften as Huckleberry Finn, Twain’s most widely read tale. Once upon a time, people hated the book because it struckthemas rude. Twain himself wrote that those who banned the book considered the novel “trash and suitable only for the slums(贫民窟).” More recently the book has been attacked because of the character Jim, the escaped slave, and many occurrences of the word nigger. (The term Nigger Jim, for which the novel is often severely criticized, never appears in it.)But the attacks were and are silly—and miss the point. The novel is strongly anti-slavery. Jim’s search through the slave states for the family from whom he has been forcibly parted is heroic. As J. Chadwick has pointed out, the character of Jim was a first in American fiction—a recognition that the slave had two personalities, “the voice of survival within a white slave culture and the voice of the individual: Jim, the father and the man.”There is much more. Twain’s mystery novel Pudd’nhead Wilson stood as a challenge to the racial beliefs of even many of the liberals of his day. Written at a time when the accepted wisdom held Negroes to be inferior (低等的) to whites, especially in intelligence, Twain’s tale centered in part around two babies switched at birth.A slave gave birth to her master’s bab y and, for fear that the child should be sold South, switched him for the master’s baby by his wife. The slave’s light-skinned child was taken to be white and grew up with both the attitudes and the education of the slave-holding class. The master’s wife’s baby was taken for black and grew up with the attitudes and intonations of the slave.The point was difficult to miss: nurture (养育), not nature, was the key to social status. The features of the black man that provided the stuff of prejudice—manner of speech, for example—were, to Twain, indicative of nothing other than the conditioning that slavery forced on its victims.Twain’s racial tone was not perfect. One is left uneasy, for example, by the lengthy passage in his autobiography (自传) about how much he loved what were called “nigger shows” in his youth—mostly with white men performing in black-face—and his delight in getting his mother to laugh at them. Yet there is no reason to think Twain saw the shows as representing reality. His frequent attacks on slavery and prejudice suggest his keen awareness that they did not.Was Twain a racist? Asking the questioning the 21 stcentury is as wise as asking the same of Lincoln. If we read the words and attitudes of the past through the “wisdom” of the considered m oral judgments of the present, we will find nothing but error. Lincoln, who believed the black man the inferior of the white, fought and won a war to free him. And Twain, raised in a slave state, briefly a soldier, and inventor of Jim, may have done more to anger the nation over racial injustice and awaken its collective conscience than any other novelist in the past century.69. How do Twain’s novels on slavery differ from Stowes?A. Twain was more willing to deal with racism.B. Twain’s attack on racism w as much less open.C. Twain’s themes seemed to agree with plots.D. Twain was openly concerned with racism.70. What best proves Twain’s anti slavery stand according to the author?A. Jim’s search for his family was described in detail.B. The slave’s voic e was first heard in American novels.C. Jim grew up into a man and a father in the white culture.D. Twain suspected that the slaves were less intelligent.71. The story of two babies switched mainly indicates that .A. slaves were forced to give up their babies to their mastersB. slaves babies could pickup slave holders‵ way of speakingC. blacks‵ social position was shaped by how they were brought upD. blacks were born with certain features of prejudice72. What does the author mainly argue for?A. Twain had done more than his contemporary writers to attack racism.B. Twain was an admirable figure comparable to Abraham Lincoln.C. Twain’s works had been banned on unreasonable grounds.D. Twain s works should be read from a historical point of view.Section BDirections:complete the following passage by using the sentences in the box. Each sentence can only be used once. Note that there are two sentences more than you need.Scientists have identified the clear biological advantages that give the world's sporting champions a head start in life before they have even begun their rigorous training programs.The coach for the French Olympic team says: “We measure special attributes between the ages of 16 and 18. But only one in 10, 000 people has the physical aspects needed to compete at the very top level in sporting events.___73___.We take into account the height, strength and endurance of a person. We also regard mental application as important, how an individual reacts when the competition gets really tou gh.”Scientists say that medical evidence is playing an increasingly important role in the selection of athletes. A study of the 40-year dominance of Kenyan runners in long distance athletic events has revealed that 45 per cent of them come from the Nandi tribe. What is remarkable is that this tribe makes up only 3 per cent of the Kenyan population.___74___. Athletic organizations consider these genetic factors a good indicator when selecting athletes to produce superior running performances.___75___.For example, David Beckham's bandy legs have been partly credited with helping to put a spin on the football when he takes a free kick for England. Other biological characteristics are more measurable. The American tennis player, AndyRoddick, has the fastest serve in the game. He is able to arch his back so much that it increases the rotation of his arm to 130 degrees. This is 44 per cent better than the average professional player and this allows him to drive the ball over the net at 240 kilometers per hour. Michael Phelps, the fourteen-times Olympic swimming champion, has over-size feet which act like flippers to propel him through the water.___76___.Mia Hamm, probably the best all-round woman footballer in the world, produces less than one liter of sweat an hour when doing vigorous exercise, which is half the human average. When it comes to speed, take the example of woman racing driver, Liz Halliday. A normal person would take 300 milliseconds to make a reactive decision. She can do it in 260 milliseconds. It may not sound much quicker but at top race speeds this makes a difference of three car lengths.The difference between success and failure is very small and all these biological factors are crucial in finding future champions.V. Productive Grammar (10 points )Directions:After reading the passage below, fill in the blanks to make the passages coherent and grammatically correct. For the blanks with a given word, fill in each blank with the proper form of the given word;for the other blanks, use one word that best fits each blank.Golden Rules of Good DesignWhat makes good design? Over the years, designers and artists __77_____(try) to capture the essentials of good design. They have found that some sayings can help people understand the ideas of good design. There are four____78_____follows.Less is more. This saying is associated with the German-born architect Mies van der Rohe. In his Modernist view, beauty lies in simplicity and elegance, and the aim of the designer is ____79_____(create) solutions to problems through the most efficient means. Design should avoid unnecessary decorations.More is not a bore. The American-born architect Robert Venturi concluded that____80___ simplicity is done badly, the result is soulless design. Post-Modernist designers began to experiment with decoration and color again. Product design was heavily influenced by this view and can be seen in kitchen appliances ____81____ ____81____ovens and kettles.Fitness for purpose. Successful product design takes into consideration a product’s function, purpose, shape, form, color, and so on.The most important result for the user is that the product does____82____is needed. For example, think of a(n) adjustable desk lamp. It needs to be constructed from materials that will stand the heat of the lamp and regular adjustments by the user. It also needs to be stable. ____83____(importantly), it needs to direct light where it is needed.From follows emotion. This phrase is associated with the German designer Hartmut Esslinger.He believes design____84____take into account the sensory side of____85____nature—sight, smell, touch and taste. These are as important as rational(理性的). When ____86____(choose)everyday products such as toothpaste, we appreciate a cool-looking device that allows us to easily squeeze the toothpaste onto our brush.VI. Translation ( 15 points )Directions: Translate the following sentences into English, using the words given in the brackets.86.不可否认鼓励学生的最好方法之一是颁发奖学金。
2016-2017学年上海市浦东新区高二(上)期中数学试卷一、填空题1.(5分)4和10的等差中项是.2.(5分)等比数列{a n}中,a1=2,公比q=3,则a5=.3.(5分)向量=(4,﹣3),则与同向的单位向量=.4.(5分)=.5.(5分)在平面直角坐标系中,已知两点A(2,﹣1)和B(﹣1,5),点P满足=2,则点P的坐标为.6.(5分)等比数列{a n}中,a2=1,a4=4,则a6=.7.(5分)S n是数列{a n}的前n项和,若a4=7,a n=a n﹣1+2(n≥2,n∈N*),则S8=.8.(5分)已知等边△ABC的边长为1,则=.9.(5分)已知向量=(1,2),=(3,﹣4),则向量在向量上的投影为.10.(5分)在数列{a n}中,S n是其前n项和,若S n=n2+1,n∈N*,则a n=.11.(5分)若等比数列{a n}的前n项和S n=()n+a(n∈N*),则数列{a n}的各项和为.12.(5分)数列{a n}中,a n+1=,a1=2,则数列{a n}的前2015项的积等于.二、选做题13.(5分)=(1,2),=(k,4),若∥,则下列结论正确的是()A.k=﹣6 B.k=2 C.k=6 D.k=﹣214.(5分)已知等差数列{a n}中,前n项和S n=n2﹣15n,则使S n有最小值的n 是()A.7 B.7或8 C.8 D.915.(5分)用数学归纳法证明1+a+a2+…+a n+1=(a≠1,n∈N*),在验证n=1成立时,左边的项是()A.1 B.1+a C.1+a+a2D.1+a+a2+a416.(5分)下列命题中,正确命题的个数是()①若2b=a+c,则a,b,c成等差数列;②“a,b,c成等比数列”的充要条件是“b2=ac”;③若数列{a n2}是等比数列,则数列{a n}也是等比数列;④若||=||,则=.A.3 B.2 C.1 D.0三、解答题17.(14分)在等差数列{a n}中,已知a1+a2=2,a2+a3=10,求通项公式a n及前n 项和S n.18.(14分)已知||=2,||=3,且向量与的夹角为,求|3﹣2|.19.(14分)已知数列满足a1=1,a n+1=2a n+1(n∈N*)(1)求证:数列{a n+1}是等比数列;(2)求{a n}的通项公式.20.(14分)已知=(m﹣2)+2,=+(m+1),其中、分别为x、y轴正方向单位向量.(1)若m=2,求与的夹角;(2)若(+)⊥(﹣),求实数m的值.21.(14分)已知各项为正的数列{a n}是等比数列,a1=2,a5=32,数列{b n}满足:对于任意n∈N*,有a1b1+a2b2+…+a n b n=(n﹣1)?2n+1+2.(1)求数列{a n}的通项公式;(2)令f(n)=a2+a4+…+a2n,求的值;(3)求数列{b n}通项公式,若在数列{a n}的任意相邻两项a k与a k+1之间插入b k (k∈N*)后,得到一个新的数列{c n},求数列{c n}的前100项之和T100.2016-2017学年上海市浦东新区高二(上)期中数学试卷参考答案与试题解析一、填空题1.(5分)4和10的等差中项是7.【分析】利用等差中项的定义即可得出.【解答】解:4和10的等差中项==7,故答案为:7.【点评】本题考查了等差中项的求法,考查了推理能力与计算能力,属于基础题.2.(5分)等比数列{a n}中,a1=2,公比q=3,则a5=162.【分析】直接利用等比数列的通项公式得答案.【解答】解:在等比数列{a n}中,由a1=2,公比q=3,得a5=.故答案为:162.【点评】本题考查等比数列的通项公式,是基础的计算题.3.(5分)向量=(4,﹣3),则与同向的单位向量=(,﹣).【分析】与向量同向的单位向量是【解答】解:∵向量=(4,﹣3),∴||==5,∴与同向的单位向量=(,﹣),故答案为:(,﹣).【点评】本题考查与一个向量同向的单位向量的求法,是基础题,解题时要熟练掌握单位向量的性质.4.(5分)=2.【分析】利用=,即可得出结论.【解答】解:==2,故答案为:2.【点评】本题考查极限运算,考查学生的计算能力,比较基础.5.(5分)在平面直角坐标系中,已知两点A(2,﹣1)和B(﹣1,5),点P满足=2,则点P的坐标为(0,3).【分析】市场P的坐标,利用向量相等,列出方程求解即可.【解答】解:设P(a,b),点A(2,﹣1)和B(﹣1,5),点P满足=2,可得(a﹣2,b+1)=2(﹣1﹣a,5﹣b),可得a﹣2=﹣2﹣2a,b+1=10﹣2b,解得a=0,b=3.点P的坐标为(0,3).故答案为:(0,3).【点评】本题考查向量相等的应用,坐标运算,考查计算能力.6.(5分)等比数列{a n}中,a2=1,a4=4,则a6=16.【分析】有已知求出q2,再由得答案.【解答】解:在等比数列{a n}中,由a2=1,a4=4,得,∴.故答案为:16.【点评】本题考查等比数列的通项公式,是基础的计算题.7.(5分)S n是数列{a n}的前n项和,若a4=7,a n=a n﹣1+2(n≥2,n∈N*),则S8= 64.【分析】利用等差数列的通项公式与求和公式即可得出.【解答】解:∵a n=a n﹣1+2(n≥2,n∈N*),∴数列{a n}是公差为2的等差数列,又a4=7,∴a1+3×2=7,解得a1=1.∴S8=8+=64.故答案为:64.【点评】本题考查了等差数列的定义通项公式与求和公式,考查了推理能力与计算能力,属于中档题.8.(5分)已知等边△ABC的边长为1,则=.【分析】由题意,等边三角形ABC的边长为1,可知两向量模已知,夹角已知,故易求.【解答】解:由题意,等边三角形ABC的边长为1,∴=﹣=﹣1×1×cos60°=﹣,故答案为:﹣.【点评】本题考查向量数量积的运算,熟练掌握向量数量积的计算公式是解题的关键,本题属于基本公式考查题,计算型.9.(5分)已知向量=(1,2),=(3,﹣4),则向量在向量上的投影为﹣1.【分析】利用向量投影的意义解答.【解答】解:由已知向量在向量上的投影为==﹣1;故答案为:﹣1.【点评】本题考查了平面向量的投影求法;利用数量积的几何意义求之即可.10.(5分)在数列{a n}中,S n是其前n项和,若S n=n2+1,n∈N*,则a n=.【分析】由S n=n2+1,n∈N*,可得n=1时,a1=S1=2;n≥2时,a n=S n﹣S n﹣1,即可得出.【解答】解:∵S n=n2+1,n∈N*,∴n=1时,a1=S1=2,n≥2时,a n=S n﹣S n﹣1=n2+1﹣[(n﹣1)2+1]=2n﹣1,则a n=.故答案为:.【点评】本题考查了数列递推关系、通项公式,考查了推理能力与计算能力,属于中档题.11.(5分)若等比数列{a n}的前n项和S n=()n+a(n∈N*),则数列{a n}的各项和为﹣1.【分析】由数列的前n项和求出首项和通项公式(n≥2),把首项代入求a,得到等比数列的通项公式,求出公比,代入无穷递缩等比数列的所有项和的公式得答案.【解答】解:由,得,=(n≥2),∵数列{a n}是等比数列,∴,得a=﹣1.∴,则,则数列{a n}的各项和为.故答案为:﹣1.【点评】本题考查等比数列的通项公式,考查了无穷递缩等比数列的所有项和的求法,是基础题.12.(5分)数列{a n}中,a n+1=,a1=2,则数列{a n}的前2015项的积等于3.【分析】通过计算出数列前几项的值,判断该数列为周期数列,进而可得结论.【解答】解:∵且a1=2,∴a2===﹣3,a3===﹣,a4===,a5===2,不难发现数列{a n}是周期数列,四个为一周期且最前四个乘积为=1,∵2015=503×4+3,∴数列{a n}前2015项的积为:=3,故答案为:3.【点评】本题考查求数列的前n项的乘积,找出其周期是解决本题的关键,注意解题方法的积累,属于中档题.二、选做题13.(5分)=(1,2),=(k,4),若∥,则下列结论正确的是()A.k=﹣6 B.k=2 C.k=6 D.k=﹣2【分析】根据平面向量平行的坐标关系解答即可.【解答】解:因为=(1,2),=(k,4),∥,所以4=2k,解得k=2;故选:B.【点评】本题考查了平面向量平行时坐标的运算关系;属于基础题.14.(5分)已知等差数列{a n}中,前n项和S n=n2﹣15n,则使S n有最小值的n 是()A.7 B.7或8 C.8 D.9【分析】S n=n2﹣15n看作关于n的二次函数.结合二次函数的图象与性质可以求解.【解答】解:S n=n2﹣15n=(n﹣)2﹣,∴数列{S n}的图象是分布在抛物线y=(x﹣)2﹣上的横坐标为正整数的离散的点.又抛物线开口向上,以x=为对称轴,且|﹣7|=|8﹣|,所以当n=7,8时,S n有最小值.故选:B.【点评】本题考查数列的函数性质,等差数列前n项和是关于n的二次函数,采用函数思想可以解决Sn的有关问题.15.(5分)用数学归纳法证明1+a+a2+…+a n+1=(a≠1,n∈N*),在验证n=1成立时,左边的项是()A.1 B.1+a C.1+a+a2D.1+a+a2+a4【分析】在验证n=1时,左端计算所得的项.把n=1代入等式左边即可得到答案.【解答】解:用数学归纳法证明1+a+a2+…+a n+1=(a≠1,n∈N*),在验证n=1时,把当n=1代入,左端=1+a+a2.故选:C.【点评】此题主要考查数学归纳法证明等式的问题,属于概念性问题.16.(5分)下列命题中,正确命题的个数是()①若2b=a+c,则a,b,c成等差数列;②“a,b,c成等比数列”的充要条件是“b2=ac”;③若数列{a n2}是等比数列,则数列{a n}也是等比数列;④若||=||,则=.A.3 B.2 C.1 D.0【分析】由等差中项的概念判断①;由充分必要条件的判断方法判断②;举例说明③④错误;【解答】解:对于①,若2b=a+c,则b﹣a=c﹣b,即a,b,c成等差数列,故①正确;对于②,由b2=ac,不一定有a,b,c成等比数列,反之,若a,b,c成等比数列,则b2=ac,∴b2=ac是a,b,c成等比数列的必要不充分条件,故②错误;对于③,若数列{a n2}是等比数列,则数列{a n}也是等比数列错误,如1,2,4成等比数列,但﹣1,﹣,2不是等比数列,故③错误;对于④,由,不一定有,如,故④错误.∴正确命题的个数是1个,故选:C.【点评】本题考查命题的真假判断与应用,考查了充分必要条件的判断方法,考查向量相等的条件,是中档题.三、解答题17.(14分)在等差数列{a n}中,已知a1+a2=2,a2+a3=10,求通项公式a n及前n 项和S n.【分析】设等差数列{a n}的公差为d,由a1+a2=2,a2+a3=10,可得2a1+d=2,2a1+3d=10,联立解得a1,d.再利用等差数列的通项公式与求和公式即可得出.【解答】解:设等差数列{a n}的公差为d,∵a1+a2=2,a2+a3=10,∴2a1+d=2,2a1+3d=10,联立解得a1=﹣1,d=4.∴通项公式a n=﹣1+4(n﹣1)=4n﹣5,前n项和S n==2n2﹣3n.【点评】本题考查了等差数列的通项公式与求和公式,考查了推理能力与计算能力,属于中档题.18.(14分)已知||=2,||=3,且向量与的夹角为,求|3﹣2|.【分析】首先由已知求出的数量积,然后利用向量的平方与其模的平方相等解答.【解答】解:|3﹣2|2==36+36﹣12×=36;|3﹣2|=6.【点评】本题考查了平面向量的模的计算;一般的,利用向量的平方与模的平方相等解答.19.(14分)已知数列满足a1=1,a n+1=2a n+1(n∈N*)(1)求证:数列{a n+1}是等比数列;(2)求{a n}的通项公式.【分析】(1)给等式a n+1=2a n+1两边都加上1,右边提取2后,变形得到等于2,所以数列{a n+1}是等比数列,得证;(2)设数列{a n+1}的公比为2,根据首项为a1+1等于2,写出数列{a n+1}的通项公式,变形后即可得到{a n}的通项公式.【解答】解:(1)由a n+1=2a n+1得a n+1+1=2(a n+1),又a n+1≠0,∴=2,即{a n+1}为等比数列;(2)由(1)知a n+1=(a1+1)q n﹣1,即a n=(a1+1)q n﹣1﹣1=2?2n﹣1﹣1=2n﹣1.第11页(共13页)【点评】此题考查学生掌握等比数列的性质并会确定一个数列为等比数列,灵活运用等比数列的通项公式化简求值,是一道综合题.20.(14分)已知=(m ﹣2)+2,=+(m+1),其中、分别为x 、y 轴正方向单位向量.(1)若m=2,求与的夹角;(2)若(+)⊥(﹣),求实数m 的值.【分析】由已知,将与坐标化,利用平面向量的坐标运算解答即可.(1)将m 代入两个向量的坐标,进行数量积的坐标运算即可;(2)分别求出+,﹣的坐标,利用向量垂直数量积为0,求出m .【解答】解:因为、分别为x 、y 轴正方向单位向量,所以=(m ﹣2,2),=(1,m+1),所以(1)m=2时,=(0,2,),=(1,3),与的夹角的余弦值,所以与的夹角为arccos ;(2)+=(m ﹣1,m+2),﹣=(m ﹣3,1﹣m ),又(+)⊥(﹣),所以(m ﹣1)(m ﹣3)+(m+2)(1﹣m )=0,即﹣5m+5=0,解得m=1.【点评】本题考查了平面向量的运算;利用已知将向量坐标化使得运算简便.21.(14分)已知各项为正的数列{a n }是等比数列,a 1=2,a 5=32,数列{b n }满足:对于任意n ∈N *,有a 1b 1+a 2b 2+…+a n b n =(n ﹣1)?2n +1+2.(1)求数列{a n }的通项公式;(2)令f (n )=a 2+a 4+…+a 2n ,求的值;(3)求数列{b n }通项公式,若在数列{a n }的任意相邻两项a k 与a k +1之间插入b k (k ∈N *)后,得到一个新的数列{c n },求数列{c n }的前100项之和T 100.【分析】(1利用q=,即可得出.。
2016-2017学年上海市浦东新区高二(上)期中数学试卷一、填空题1.(5分)4和10的等差中项是.2.(5分)等比数列{a n}中,a1=2,公比q=3,则a5=.3.(5分)向量=(4,﹣3),则与同向的单位向量=.4.(5分)=.5.(5分)在平面直角坐标系中,已知两点A(2,﹣1)和B(﹣1,5),点P满足=2,则点P的坐标为.6.(5分)等比数列{a n}中,a2=1,a4=4,则a6=.7.(5分)S n是数列{a n}的前n项和,若a4=7,a n=a n﹣1+2(n≥2,n∈N*),则S8=.8.(5分)已知等边△ABC的边长为1,则=.9.(5分)已知向量=(1,2),=(3,﹣4),则向量在向量上的投影为.10.(5分)在数列{a n}中,S n是其前n项和,若S n=n2+1,n∈N*,则a n=.11.(5分)若等比数列{a n}的前n项和S n=()n+a(n∈N*),则数列{a n}的各项和为.12.(5分)数列{a n}中,a n+1=,a1=2,则数列{a n}的前2015项的积等于.二、选做题13.(5分)=(1,2),=(k,4),若∥,则下列结论正确的是()A.k=﹣6 B.k=2 C.k=6 D.k=﹣214.(5分)已知等差数列{a n}中,前n项和S n=n2﹣15n,则使S n有最小值的n 是()A.7 B.7或8 C.8 D.915.(5分)用数学归纳法证明1+a+a2+…+a n+1=(a≠1,n∈N*),在验证n=1成立时,左边的项是()A.1 B.1+a C.1+a+a2D.1+a+a2+a416.(5分)下列命题中,正确命题的个数是()①若2b=a+c,则a,b,c成等差数列;②“a,b,c成等比数列”的充要条件是“b2=ac”;③若数列{a n2}是等比数列,则数列{a n}也是等比数列;④若||=||,则=.A.3 B.2 C.1 D.0三、解答题17.(14分)在等差数列{a n}中,已知a1+a2=2,a2+a3=10,求通项公式a n及前n 项和S n.18.(14分)已知||=2,||=3,且向量与的夹角为,求|3﹣2|.19.(14分)已知数列满足a1=1,a n+1=2a n+1(n∈N*)(1)求证:数列{a n+1}是等比数列;(2)求{a n}的通项公式.20.(14分)已知=(m﹣2)+2,=+(m+1),其中、分别为x、y轴正方向单位向量.(1)若m=2,求与的夹角;(2)若(+)⊥(﹣),求实数m的值.21.(14分)已知各项为正的数列{a n}是等比数列,a1=2,a5=32,数列{b n}满足:对于任意n∈N*,有a1b1+a2b2+…+a n b n=(n﹣1)•2n+1+2.(1)求数列{a n}的通项公式;(2)令f(n)=a2+a4+…+a2n,求的值;之间插入b k (3)求数列{b n}通项公式,若在数列{a n}的任意相邻两项a k与a k+1(k∈N*)后,得到一个新的数列{c n},求数列{c n}的前100项之和T100.2016-2017学年上海市浦东新区高二(上)期中数学试卷参考答案与试题解析一、填空题1.(5分)4和10的等差中项是7.【解答】解:4和10的等差中项==7,故答案为:7.2.(5分)等比数列{a n}中,a1=2,公比q=3,则a5=162.【解答】解:在等比数列{a n}中,由a1=2,公比q=3,得a5=.故答案为:162.3.(5分)向量=(4,﹣3),则与同向的单位向量=(,﹣).【解答】解:∵向量=(4,﹣3),∴||==5,∴与同向的单位向量=(,﹣),故答案为:(,﹣).4.(5分)=2.【解答】解:==2,故答案为:2.5.(5分)在平面直角坐标系中,已知两点A(2,﹣1)和B(﹣1,5),点P满足=2,则点P的坐标为(0,3).【解答】解:设P(a,b),点A(2,﹣1)和B(﹣1,5),点P满足=2,可得(a﹣2,b+1)=2(﹣1﹣a,5﹣b),可得a﹣2=﹣2﹣2a,b+1=10﹣2b,解得a=0,b=3.点P的坐标为(0,3).故答案为:(0,3).6.(5分)等比数列{a n}中,a2=1,a4=4,则a6=16.【解答】解:在等比数列{a n}中,由a2=1,a4=4,得,∴.故答案为:16.7.(5分)S n是数列{a n}的前n项和,若a4=7,a n=a n﹣1+2(n≥2,n∈N*),则S8= 64.【解答】解:∵a n=a n﹣1+2(n≥2,n∈N*),∴数列{a n}是公差为2的等差数列,又a4=7,∴a1+3×2=7,解得a1=1.∴S8=8+=64.故答案为:64.8.(5分)已知等边△ABC的边长为1,则=.【解答】解:由题意,等边三角形ABC的边长为1,∴=﹣=﹣1×1×cos60°=﹣,故答案为:﹣.9.(5分)已知向量=(1,2),=(3,﹣4),则向量在向量上的投影为﹣1.【解答】解:由已知向量在向量上的投影为==﹣1;故答案为:﹣1.10.(5分)在数列{a n}中,S n是其前n项和,若S n=n2+1,n∈N*,则a n=.【解答】解:∵S n=n2+1,n∈N*,∴n=1时,a 1=S1=2,n≥2时,a n=S n﹣S n﹣1=n2+1﹣[(n﹣1)2+1]=2n﹣1,则a n=.故答案为:.11.(5分)若等比数列{a n}的前n项和S n=()n+a(n∈N*),则数列{a n}的各项和为﹣1.【解答】解:由,得,=(n≥2),∵数列{a n}是等比数列,∴,得a=﹣1.∴,则,则数列{a n}的各项和为.故答案为:﹣1.12.(5分)数列{a n}中,a n+1=,a1=2,则数列{a n}的前2015项的积等于3.【解答】解:∵且a1=2,∴a2===﹣3,a3===﹣,a4===,a5===2,不难发现数列{a n}是周期数列,四个为一周期且最前四个乘积为=1,∵2015=503×4+3,∴数列{a n}前2015项的积为:=3,故答案为:3.二、选做题13.(5分)=(1,2),=(k,4),若∥,则下列结论正确的是()A.k=﹣6 B.k=2 C.k=6 D.k=﹣2【解答】解:因为=(1,2),=(k,4),∥,所以4=2k,解得k=2;故选:B.14.(5分)已知等差数列{a n}中,前n项和S n=n2﹣15n,则使S n有最小值的n 是()A.7 B.7或8 C.8 D.9【解答】解:S n=n2﹣15n=(n﹣)2﹣,∴数列{S n}的图象是分布在抛物线y=(x﹣)2﹣上的横坐标为正整数的离散的点.又抛物线开口向上,以x=为对称轴,且|﹣7|=|8﹣|,所以当n=7,8时,S n有最小值.故选:B.15.(5分)用数学归纳法证明1+a+a2+…+a n+1=(a≠1,n∈N*),在验证n=1成立时,左边的项是()A.1 B.1+a C.1+a+a2D.1+a+a2+a4【解答】解:用数学归纳法证明1+a+a2+…+a n+1=(a≠1,n∈N*),在验证n=1时,把当n=1代入,左端=1+a+a2.故选:C.16.(5分)下列命题中,正确命题的个数是()①若2b=a+c,则a,b,c成等差数列;②“a,b,c成等比数列”的充要条件是“b2=ac”;③若数列{a n2}是等比数列,则数列{a n}也是等比数列;④若||=||,则=.A.3 B.2 C.1 D.0【解答】解:对于①,若2b=a+c,则b﹣a=c﹣b,即a,b,c成等差数列,故①正确;对于②,由b2=ac,不一定有a,b,c成等比数列,反之,若a,b,c成等比数列,则b2=ac,∴b2=ac是a,b,c成等比数列的必要不充分条件,故②错误;对于③,若数列{a n2}是等比数列,则数列{a n}也是等比数列错误,如1,2,4成等比数列,但﹣1,﹣,2不是等比数列,故③错误;对于④,由,不一定有,如,故④错误.∴正确命题的个数是1个,故选:C.三、解答题17.(14分)在等差数列{a n}中,已知a1+a2=2,a2+a3=10,求通项公式a n及前n 项和S n.【解答】解:设等差数列{a n}的公差为d,∵a1+a2=2,a2+a3=10,∴2a1+d=2,2a1+3d=10,联立解得a1=﹣1,d=4.∴通项公式a n=﹣1+4(n﹣1)=4n﹣5,前n项和S n==2n2﹣3n.18.(14分)已知||=2,||=3,且向量与的夹角为,求|3﹣2|.【解答】解:|3﹣2|2==36+36﹣12×=36;|3﹣2|=6.19.(14分)已知数列满足a1=1,a n+1=2a n+1(n∈N*)(1)求证:数列{a n+1}是等比数列;(2)求{a n}的通项公式.=2a n+1得a n+1+1=2(a n+1),【解答】解:(1)由a n+1又a n+1≠0,∴=2,即{a n+1}为等比数列;(2)由(1)知a n+1=(a1+1)q n﹣1,即a n=(a1+1)q n﹣1﹣1=2•2n﹣1﹣1=2n﹣1.20.(14分)已知=(m﹣2)+2,=+(m+1),其中、分别为x、y轴正方向单位向量.(1)若m=2,求与的夹角;(2)若(+)⊥(﹣),求实数m的值.【解答】解:因为、分别为x、y轴正方向单位向量,所以=(m﹣2,2),=(1,m+1),所以(1)m=2时,=(0,2,),=(1,3),与的夹角的余弦值,所以与的夹角为arccos;(2)+=(m﹣1,m+2),﹣=(m﹣3,1﹣m),又(+)⊥(﹣),所以(m﹣1)(m﹣3)+(m+2)(1﹣m)=0,即﹣5m+5=0,解得m=1.21.(14分)已知各项为正的数列{a n}是等比数列,a1=2,a5=32,数列{b n}满足:对于任意n∈N*,有a1b1+a2b2+…+a n b n=(n﹣1)•2n+1+2.(1)求数列{a n}的通项公式;(2)令f(n)=a2+a4+…+a2n,求的值;之间插入b k (3)求数列{b n}通项公式,若在数列{a n}的任意相邻两项a k与a k+1(k∈N*)后,得到一个新的数列{c n},求数列{c n}的前100项之和T100.【解答】解:(1)∵a1=2,a5=32,∴q==2,∴a n=2n.(2)f(n)=a2+a4+…+a2n=22+24+…+22n==,f(n+1)=.∴===4.(3)∵a1b1+a2b2+…+a n b n=(n﹣1)•2n+1+2,∴当n≥2时,a1b1+a2b2+…+a n﹣1b n﹣1=(n﹣2)•2n+2,两式相减得:a n b n=(n﹣1)•2n+1+2﹣(n﹣2)•2n+2=n•2n,即b n==n(n≥2),又∵a1b1=2,即b1=1满足上式,∴b n=n;设S n表示数列{c n}的前n项之和,S100=(a1+a2+…+a50)+(b1+b2+…+b50)=2+22+…+250+1+2+…+50=+=251+1273.赠送初中数学几何模型【模型五】垂直弦模型:图形特征:运用举例:1.已知A、B、C、D是⊙O上的四个点.(1)如图1,若∠ADC=∠BCD=90°,AD=CD,求证AC⊥BD;(2)如图2,若AC⊥BD,垂足为E,AB=2,DC=4,求⊙O的半径.O DAB CEAOD CB2.如图,已知四边形ABCD 内接于⊙O ,对角线AC ⊥BD 于P ,设⊙O 的半径是2。
2015-2016学年上海市复旦大学附中高二(上)期末数学试卷一、填空题(共48分,每空4分)1.抛物线C的顶点在坐标原点,焦点在坐标轴上,且C过点(﹣2,3),则C 的方程是.2.若过点P(2,2)可以向圆x2+y2﹣2kx﹣2y+k2﹣k=0作两条切线,则实数k的取值范围是.3.参数方程(θ∈R)化为普通方程是.4.M是椭圆上动点,F1,F2是椭圆的两焦点,则∠F1MF2的最大值为.5.圆x2+(y﹣a)2=9与椭圆有公共点,则实数a的取值范围是.6.与圆x2+y2﹣4x=0外切,且与y轴相切的动圆圆心的轨迹方程是.7.双曲线2x2﹣3y2=k(k<0)的焦点坐标是(用k表示).8.已知P(x,y)是圆(x+1)2+y2=1上一点,则2x+3y的最大值为.9.若直线与圆x2+y2=1在第一象限有两个不同的交点,则实数a的取值范围是.10.椭圆E:的右顶点为B,过E的右焦点作斜率为1的直线L与E交于M,N两点,则△MBN的面积为.11.设实数x,y满足x2=4y,则的最小值是.12.椭圆C:向右平移一个单位、向上平移两个单位可以得到椭圆C′:.设直线l:(2a+1)x+(1﹣a)y﹣3=0,当实数a变化时,l被C′截得的最大弦长是.二、选择题(共20分,每题5分)13.圆x2+y2+2x+4y﹣3=0上到直线x+y+1=0的距离为的点有()A.1个 B.2个 C.3个 D.4个14.“ab<0”是“方程ax2+by2=c表示双曲线”的()A.充分必要条件B.充分不必要条件C.必要不充分条件 D.既不必要也不充分条件15.过点(3,0)和双曲线x2﹣ay2=1(a>0)仅有一交点的直线有()A.1条 B.2条 C.4条 D.不确定16.双曲线C的左、右焦点为F1,F2,P为C的右支上动点(非顶点),I为△F1PF2的内心.当P变化时,I的轨迹为()A.双曲线的一部分 B.椭圆的一部分C.直线的一部分D.无法确定三、解答题(共52分,8+10+10+12+12)17.已知抛物线C:y=2x2和直线l:y=kx+1,O为坐标原点.(1)求证:l与C必有两交点;(2)设l与C交于A,B两点,且直线OA和OB斜率之和为1,求k的值.18.斜率为1的动直线L与椭圆交于P,Q两点,M是L上的点,且满足|MP|•|MQ|=2,求点M的轨迹方程.19.已知椭圆x2+2y2=1上存在两点A,B关于直线L:y=4x+b对称,求实数b的取值范围.20.已知双曲线C的渐近线方程为x±2y=0,且点A(5,0)到双曲线上动点P的最小距离为,求C的方程.21.设定点A(0,1),常数m>2,动点M(x,y),设,,且.(1)求动点M的轨迹方程;(2)设直线L:与点M的轨迹交于B,C两点,问是否存在实数m使得?若存在,求出m的值;若不存在,请说明理由.2015-2016学年上海市复旦大学附中高二(上)期末数学试卷参考答案与试题解析一、填空题(共48分,每空4分)1.抛物线C的顶点在坐标原点,焦点在坐标轴上,且C过点(﹣2,3),则C的方程是y2=﹣x或x2=y.【考点】抛物线的简单性质.【分析】对称轴分为是x轴和y轴两种情况,分别设出标准方程为y2=﹣2px和x2=2py,然后将(﹣2,3),代入即可求出抛物线标准方程.【解答】解:(1)抛物线的顶点在坐标原点,对称轴是x轴,并且经过点(﹣2,3),设它的标准方程为y2=﹣2px(p>0),∴9=4p解得:2p=,∴y2=﹣x;(2)对称轴是y轴,并且经过点(﹣2,3),抛物线的方程为x2=2py(p>0),∴4=6p,得:2p=,∴抛物线的方程为:x2=y.所以所求抛物线的标准方程为:y2=﹣x或x2=y.故答案为:y2=﹣x或x2=y.2.若过点P(2,2)可以向圆x2+y2﹣2kx﹣2y+k2﹣k=0作两条切线,则实数k的取值范围是(﹣1,1)∪(4,+∞).【考点】圆的切线方程.【分析】将圆化成标准方程,得(x﹣k)2+(y﹣1)2=k+1,根据方程表示圆的条件和点与圆的位置关系,结合题意建立关于k的不等式组,解之即可得到实数k 的取值范围.【解答】解:圆x2+y2﹣2kx﹣2y+k2﹣k=0,可化为(x﹣k)2+(y﹣1)2=k+1.∵方程x2+y2﹣2kx﹣2y+k2﹣k=0表示圆,∴k+1>0,解之得k>﹣1.又∵过点P(2,2)可以向圆x2+y2﹣2kx﹣2y+k2﹣k=0作两条切线,∴点P(2,2)在圆外,可得(2﹣k)2+(2﹣1)2>k+1,解之得k<1或k>4综上所述,可得k的取值范围是(﹣1,1)∪(4,+∞),故答案为(﹣1,1)∪(4,+∞).3.参数方程(θ∈R)化为普通方程是x2+(y﹣1)2=1.【考点】参数方程化成普通方程.【分析】利用同角三角函数平方关系,可得结论.【解答】解:由题意,消去参数θ,可得普通方程是x2+(y﹣1)2=1,故答案为x2+(y﹣1)2=1.4.M是椭圆上动点,F1,F2是椭圆的两焦点,则∠F1MF2的最大值为π﹣arccos.【考点】椭圆的简单性质.【分析】求得椭圆的a,b,c,由椭圆中焦点三角形中,焦距所对角最大,可得∠F1MF2最大,此时M为短轴端点.再由余弦定理,计算即可得到所求最大角.【解答】解:椭圆的a=3,b=1,c==2,由椭圆中焦点三角形中,焦距所对角最大,可得∠F1MF2最大,此时M为短轴端点.则cos∠F1MF2===﹣,可得∠F1MF2的最大值为π﹣arccos.故答案为:π﹣arccos.5.圆x2+(y﹣a)2=9与椭圆有公共点,则实数a的取值范围是[﹣6,6] .【考点】椭圆的简单性质.【分析】由题意可知:椭圆焦点在x轴上,a=5,b=3,圆x2+(y﹣a)2=9的圆心坐标(0,a),半径r=3.若椭圆1与圆x2+(y﹣a)2=9有公共点,根据图象可知数a的取值范围.【解答】解:∵椭圆焦点在x轴上,a=5,b=3,|x|≤5,|y|≤4,圆x2+(y﹣a)2=9的圆心坐标(0,a),半径r=3.∴若椭圆1与圆x2+(y﹣a)2=9有公共点,则实数a的取值范围|a|≤6;故答案为:[﹣6,6].6.与圆x2+y2﹣4x=0外切,且与y轴相切的动圆圆心的轨迹方程是y2=8x(x>0)或y=0(x<0).【考点】轨迹方程;抛物线的定义.【分析】分动圆在y轴右侧和动圆在y轴左侧两种情况考虑,若动圆在y轴右侧,则动圆圆心到定点(2,0)与到定直线x=﹣2的距离相等,利用抛物线的定义求轨迹方程,若动圆在y轴左侧,动圆圆心轨迹是x负半轴.【解答】解:若动圆在y轴右侧,则动圆圆心到定点(2,0)与到定直线x=﹣2的距离相等,其轨迹是抛物线;且=2,其方程为y2=8x,若动圆在y轴左侧,则动圆圆心轨迹是x负半轴,方程为y=0,x≤0,故答案为y2=8x,或y=0,x≤0.7.双曲线2x2﹣3y2=k(k<0)的焦点坐标是(用k表示)(0,±).【考点】双曲线的简单性质.【分析】双曲线2x2﹣3y2=k(k<0),化为=1,即可求得c.【解答】解;双曲线2x2﹣3y2=k(k<0),化为=1,根据双曲线方程可知c==,∴双曲线焦点坐标为(0,±)故答案为(0,±).8.已知P(x,y)是圆(x+1)2+y2=1上一点,则2x+3y的最大值为﹣2.【考点】圆的标准方程.【分析】假设点P的坐标为(﹣1+cosα,sinα),利用三角函数,可求最值.【解答】解:圆的标准方程为(x+1)2+y2=1,设P(﹣1+cosα,sinα),则2x+3y=2cosα+3sinα﹣2=cos(α+θ)﹣2∴2x+3y的最大值为:﹣2.故答案为:﹣2.9.若直线与圆x2+y2=1在第一象限有两个不同的交点,则实数a的取值范围是(,2).【考点】直线与圆的位置关系.【分析】抓住两个关键点,一是直线过(0,1);一是直线与圆相切,分别求出m的值,即可确定出直线与圆在第一象限内有两个不同的交点时a的范围.【解答】解:分两种情况:当直线过(0,1)时,将x=0,y=1代入得:a=;当直线与圆x2+y2=1相切时,圆心到直线的距离d==r=1,解得:a=2或﹣2(舍去),则直线与圆在第一象限内有两个不同的交点时,实数a的取值范围是(,2).故答案为(,2).10.椭圆E:的右顶点为B,过E的右焦点作斜率为1的直线L与E交于M,N两点,则△MBN的面积为,.【考点】椭圆的简单性质.【分析】由椭圆E:右焦点(1,0),右顶点(2,0),设直线L的方程为y=x﹣1,代入椭圆方程,由韦达定理及弦长公式求得丨MN丨,则B到直线L的距离d==,△MBN的面积S=•丨MN丨•d.【解答】解:由题意可知:椭圆E:右焦点(1,0),右顶点(2,0),设直线L的方程为y=x﹣1,M(x1,y1),N(x2,y2),由,整理得:7x2﹣8x﹣8=0,由韦达定理可知:x1+x2=,x1x2=﹣,丨MN丨=•=•=,则B到直线L的距离d==,△MBN的面积S=•丨MN丨•d=××=,∴△MBN的面积为,故答案为:.11.设实数x,y满足x2=4y,则的最小值是2.【考点】抛物线的简单性质.【分析】抛物线的准线方程为y=﹣1, +1﹣1最小值是(3,1)与焦点(0,1)的距离减去1,可得结论.【解答】解:抛物线的准线方程为y=﹣1, +1﹣1最小值是(3,1)与焦点(0,1)的距离减去1,即的最小值是3﹣1=2,故答案为2.12.椭圆C:向右平移一个单位、向上平移两个单位可以得到椭圆C′:.设直线l:(2a+1)x+(1﹣a)y﹣3=0,当实数a变化时,l被C′截得的最大弦长是8.【考点】椭圆的简单性质.【分析】直线l:(2a+1)x+(1﹣a)y﹣3=0,化为:a(2x﹣y)+(x+y﹣3)=0,利用直线系的性质可得:直线l经过定点M(1,2),为椭圆C′:的中心.因此当实数a变化时,l被C′截得的最大弦长是2a.【解答】解:直线l:(2a+1)x+(1﹣a)y﹣3=0,化为:a(2x﹣y)+(x+y﹣3)=0,令,解得x=1,y=2,因此直线l经过定点M(1,2),为椭圆C′:的中心.因此当实数a变化时,l被C′截得的最大弦长是2a=8.故答案为:8.二、选择题(共20分,每题5分)13.圆x2+y2+2x+4y﹣3=0上到直线x+y+1=0的距离为的点有()A.1个 B.2个 C.3个 D.4个【考点】直线与圆的位置关系.【分析】圆x2+y2+2x+4y﹣3=0可化为(x+1)2+(y+2)2=8,过圆心平行于直线x+y+1=0的直线与圆有两个交点,另一条与直线x+y+1=0的距离为的平行线与圆相切,只有一个交点.【解答】解:圆x2+y2+2x+4y﹣3=0可化为(x+1)2+(y+2)2=8∴圆心坐标是(﹣1,﹣2),半径是2;∵圆心到直线的距离为d==,∴过圆心平行于直线x+y+1=0的直线与圆有两个交点,另一条与直线x+y+1=0的距离为的平行线与圆相切,只有一个交点所以,共有3个交点.故选:C14.“ab<0”是“方程ax2+by2=c表示双曲线”的()A.充分必要条件B.充分不必要条件C.必要不充分条件 D.既不必要也不充分条件【考点】必要条件、充分条件与充要条件的判断.【分析】运用反例,特殊值,结合双曲线的标准方程判断.【解答】解:若a=1,b=﹣1,c=0,则不能表示双曲线,不是充分条件,反之,若方程ax2+by2=c表示双曲线,则a,b异号,是必要条件,故ab<0是方程ax2+by2=c表示双曲线的必要不充分条件,故选:C.15.过点(3,0)和双曲线x2﹣ay2=1(a>0)仅有一交点的直线有()A.1条 B.2条 C.4条 D.不确定【考点】双曲线的简单性质.【分析】直线斜率不存在时,不满足条件,直线斜率存在时,与渐近线平行的直线,满足题意,可得结论.【解答】解:直线斜率不存在时,满不足条件;直线斜率存在时,与渐近线平行的直线,满足题意,∴过点(3,0)和双曲线x2﹣ay2=1(a>0)仅有一交点的直线有2条.故选:B.16.双曲线C的左、右焦点为F1,F2,P为C的右支上动点(非顶点),I为△F1PF2的内心.当P变化时,I的轨迹为()A.双曲线的一部分 B.椭圆的一部分C.直线的一部分D.无法确定【考点】轨迹方程.【分析】将内切圆的圆心坐标进行转化成圆与横轴切点Q的横坐标,PF1﹣PF2=F1Q ﹣F2Q=2a,F1Q+F2Q=F1F2解出OQ,可得结论.【解答】解:如图设切点分别为M,N,Q,则△PF1F2的内切圆的圆心的横坐标与Q横坐标相同.由双曲线的定义,PF1﹣PF2=2a=4.由圆的切线性质PF1﹣PF2=F I M﹣F2N=F1Q﹣F2Q=2a,∵F1Q+F2Q=F1F2=2c,∴F1Q=a+c,F2Q=c﹣a,∴OQ=F1F2﹣QF2=c﹣(c﹣a)=a.∴△F1PF2内切圆与x轴的切点坐标为(a,0),∴当P变化时,I的轨迹为直线的一部分.故选C.三、解答题(共52分,8+10+10+12+12)17.已知抛物线C:y=2x2和直线l:y=kx+1,O为坐标原点.(1)求证:l与C必有两交点;(2)设l与C交于A,B两点,且直线OA和OB斜率之和为1,求k的值.【考点】抛物线的简单性质.【分析】(1)联立抛物线C:y=2x2和直线l:y=kx+1,可得2x2﹣kx﹣1=0,利用△>0,即可证明l与C必有两交点;(2)根据直线OA和OB斜率之和为1,利用韦达定理可得k的值.【解答】(1)证明:联立抛物线C:y=2x2和直线l:y=kx+1,可得2x2﹣kx﹣1=0,∴△=k2+8>0,∴l与C必有两交点;(2)解:设A(x1,y1),B(x2,y2),则+=1①因为y1=kx1+1,y2=kx2+1,代入①,得2k+(+)=1②因为x1+x2=k,x1x2=﹣,代入②得k=1.18.斜率为1的动直线L与椭圆交于P,Q两点,M是L上的点,且满足|MP|•|MQ|=2,求点M的轨迹方程.【考点】椭圆的简单性质.【分析】设直线L的方程为:y=x+t,P(x1,y1),Q(x2,y2),M(m,n).可得y1=x1+t,y2=x2+t,t=n﹣m.直线方程与椭圆方程联立可得:3x2+4tx+2t2﹣4=0,|MP|==,同理可得:|MQ|=.利用|MP|•|MQ|=2,代入化简即可得出.【解答】解:设直线L的方程为:y=x+t,P(x1,y1),Q(x2,y2),M(m,n).则y1=x1+t,y2=x2+t,t=n﹣m.联立,化为:3x2+4tx+2t2﹣4=0,△=16t2﹣12(2t2﹣4)>0,解得:t2<6.∴x1+x2=﹣,.|MP|==,同理可得:|MQ|=.∵|MP|•|MQ|=2,∴1=|(x1﹣m)(x2﹣m)|=,∴m2+2n2=1或7.∴点M的轨迹为椭圆,其方程为m2+2n2=1或7.19.已知椭圆x2+2y2=1上存在两点A,B关于直线L:y=4x+b对称,求实数b的取值范围.【考点】椭圆的简单性质.【分析】将A,B坐标代入椭圆方程,利用作差法,求得直线AB的斜率,由直线AB的斜率为﹣,代入求得AB中点M(x0,y0),横坐标和纵坐标与m的关系,代入x2+2y2<1,即可求得b的取值范围.【解答】解:∵椭圆x2+2y2=1,焦点在x轴上,设椭圆上两点A(x1,y1)、B(x2,y2)关于直线y=4x+b对称,AB中点为M(x0,y0),直线AB的斜率为﹣则x12+2y12=1,①x22+2y22=1,②①﹣②得:(x1+x2)(x1﹣x2)+2(y1+y2)(y1﹣y2)=0,由中点坐标公式可知:x1+x2=2x0,y1+y2=2y0,即2x0•(x1﹣x2)+2•2y0•(y1﹣y2)=0,∴=﹣•=﹣.∴y0=x0,代入直线方程y=4x+b得x0=﹣b,y0=﹣b;∵(x0,y0)在椭圆内部,∴+2×<1,即6b2<49,解得﹣<b<.实数b的取值范围(﹣,).20.已知双曲线C的渐近线方程为x±2y=0,且点A(5,0)到双曲线上动点P的最小距离为,求C的方程.【考点】双曲线的简单性质.【分析】由已知条件,设双曲线方程﹣y2=λ,λ≠0,由定点A(50)到双曲线C上的动点P的最小距离为,运用两点距离公式,结合二次函数最值求法,可得最小值,求得λ,由此能求出双曲线方程.【解答】解:∵双曲线C的一条渐近线L的方程为x±2y=0,∴设双曲线方程为﹣y2=λ,λ≠0设P(m,n),则m2﹣4n2=4λ,点A(5,0)到双曲线上动点P的距离为:===,当m=4时,上式取得最小值,由题意可得=,解得λ=﹣1.则双曲线C的方程为y2﹣=1.21.设定点A(0,1),常数m>2,动点M(x,y),设,,且.(1)求动点M的轨迹方程;(2)设直线L:与点M的轨迹交于B,C两点,问是否存在实数m使得?若存在,求出m的值;若不存在,请说明理由.【考点】双曲线的简单性质;轨迹方程.【分析】(1)根据向量的表达式,可推断出点M(x,y)到两个定点F1(﹣m,0),F2(m,0)的距离之差4,根据双曲线的定义判断出其轨迹为双曲线,进而根据c和a,求得b,则其方程可得.(2)设将直线的方程代入椭圆的方程,消去y得到关于x的一元二次方程,再结合根与系数的关系利用向量数量积的坐标公式即可求得m值,从而解决问题.【解答】解:(1)由题意,﹣=4<2m,∴动点M的轨迹是以(﹣m,0),(m,0)为焦点的双曲线的右支,方程为=1(x≥2);(2)由直线L:与点M的轨迹方程,联立可得(m2﹣5)x2+12x﹣36﹣4(m2﹣4)=0,设B(x1,y1),C(x2,y2),则x1+x2=﹣,x1x2=,∵,∴x1x2+(y1﹣1)(y2﹣1)=,∴x1x2﹣2(x1+x2)+16=,∴m2=9,m=±3,∵m≥2,∴m=3检验m=3时x1+x2=﹣3<0,所以不存在m.2017年3月19日。