河南省新野三高2020届高三数学8月第一次阶段性考试试卷文(无答案)
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2020年河南省八市中评高考数学三模试卷(文科)一、选择题:本大题共12小题,每小题5分,共60分.在每个小题给出的四个选项中,有且只有一项符合题目要求.1.已知复数(i是虚数单位),则|z|=()A.5 B.C.D.12.已知,则B中的元素的个数为()A.1 B.2 C.4 D.83.某学生一个学期的数学测试成绩一共记录了6个数据:x1=52,x2=70,x3=68,x4=55,x5=85,x6=90,执行如图所示的程序框图,那么输出的S是()A.1 B.2 C.3 D.44.设a,b是不同的直线,α,β是不同的平面,则下列四个命题中错误的是()A.若a⊥b,a⊥α,b⊄α,则b∥αB.若a∥α,a⊥β,则α⊥βC.若a⊥β,α⊥β,则a∥αD.若a⊥b,a⊥α,b⊥β,则α⊥β5.已知x,y满足,若存在x,y使得2x+y≤a成立,则a的取值范围是()A.(2,+∞)B.[2,+∞)C.[4,+∞)D.[10,+∞)6.某几何体的三视图如图所示,则该几何体的体积为()A.4 B.2 C.6 D.7.数列{a n}满足a n+1(a n﹣1﹣a n)=a n﹣1(a n﹣a n+1),若a1=2,a2=1,则a20=()A. B.C.D.8.长为的线段AB在双曲线x2﹣y2=1的一条渐近线上移动,C为抛物线y=﹣x2﹣2上的点,则△ABC面积的最小值是()A.B.C.D.79.已知圆x2+y2=4的动弦AB恒过点(1,1),若弦长AB为整数,则直线AB的条数是()A.2 B.3 C.4 D.510.将函数的图象向右平移θ(θ>0)个单位长度后关于y轴对称,则θ的最小值是()A.B.C.D.11.已知三棱锥S﹣ABC的底面△ABC为正三角形,顶点在底面上的射影为底面的中心,M,N分别是棱SC,BC的中点,且MN⊥AM,若侧棱,则三棱锥S﹣ABC的外接球的表面积是()A.12π B.32π C.36π D.48π12.若函数f(x)=xlnx﹣ax2有两个极值点,则实数a的取值范围是()A. B. C.(1,2)D.(2,e)二、填空题:本大题共4小题,每小题5分,共20分.13.已知=(﹣2,2),=(1,0),若向量=(1,﹣2)使﹣λ共线,则λ=.14.一组数据1,10,5,2,x,2,且2<x<5,若该数据的众数是中位数的倍,则该数据的方差为.15.非零实数a,b满足tanx=x,且a2≠b2,则(a﹣b)sin(a+b)﹣(a+b)sin(a﹣b)= .16.已知椭圆的左、右焦点分别为F1,F2,左右顶点分别为A1,A2,P为椭圆上任意一点(不包括椭圆的顶点),则以线段PF i(i=1,2)为直径的圆与以A1A2为直径的圆的位置关系为.三、解答题:本大题共5小题,共70分.解答应写出必要的文字说明或推理、验算过程. 17.已知三角形ABC中,角A,B,C的对边分别为a,b,c,若,且角A 为锐角.(1)求三角形内角A的大小;(2)若a=5,b=8,求c的值.18.如图,ABC﹣A'B'C'为直三棱柱,M为CC的中点,N为AB的中点,AA'=BC=3,AB=2,AC=.(1)求证:CN∥平面AB'M;(2)求三棱锥B'﹣AMN的体积.19.为考查某种疫苗的效果,进行动物实验,得到如下疫苗效果的实验列联表:感染未感染总计没服用 20 50服用 40总计 100(1)请完成上面的列联表,并回答是否有97.5%的把握认为这种疫苗有效?并说明理由;(2)利用分层抽样的方法在感染的动物中抽取6只,然后在所抽取的6只动物中任取2只,问至少有1只服用疫苗的概率是多少?参考公式:K2=参考数值:P(K2≥k0) 0.05 0.025 0.010 k0 3.841 5.024 6.635 20.一张坐标纸上涂着圆E:(x+1)2+y2=8及点P(1,0),折叠此纸片,使P与圆周上某点P'重合,每次折叠都会留下折痕,设折痕与EP'的交点为M.(1)求M的轨迹C的方程;(2)直线l:y=kx+m与C的两个不同交点为A,B,且l与以EP为直径的圆相切,若,求△ABO的面积的取值范围.21.已知函数f(x)=mx+2lnx+,m∈R.(1)讨论函数f(x)的单调性;(2)设函数g(x)=,若至少存在一个x0∈[1,e],使得f(x0)>g(x0)成立,求实数m的取值范围.[选修4-4:参数方程与极坐标系]22.在平面直角坐标系xoy中,以坐标原点O为极点,x轴的正半轴为极轴的极坐标系中,曲线C的极坐标方程为,且曲线C在极坐标系中过点(2,π).(1)求曲线C的直角坐标方程;(2)设直线(t为参数)与曲线C相交于A,B两点,直线m过线段AB 的中点,且倾斜角是直线l的倾斜角的2倍,求m的极坐标方程.[选修4-5:不等式选讲]23.已知函数f(x)=|x﹣1|+|x﹣a|(a>0),其最小值为3.(1)求实数a的值;(2)若关于x的不等式f(x)+|x|>m2﹣2m对于任意的x∈R恒成立,求实数m的取值范围.2020年河南省八市中评高考数学三模试卷(文科)参考答案与试题解析一、选择题:本大题共12小题,每小题5分,共60分.在每个小题给出的四个选项中,有且只有一项符合题目要求.1.已知复数(i是虚数单位),则|z|=()A.5 B.C.D.1【考点】A5:复数代数形式的乘除运算.【分析】利用复数代数形式的乘除运算化简,再由模的计算公式求解.【解答】解:∵ =,∴|z|=.故选:D.2.已知,则B中的元素的个数为()A.1 B.2 C.4 D.8【考点】12:元素与集合关系的判断.【分析】求出B={1,4},由此能求出B中的元素的个数.【解答】解:∵,∴B={1,4},∴B中的元素的个数为2.故选:B.3.某学生一个学期的数学测试成绩一共记录了6个数据:x1=52,x2=70,x3=68,x4=55,x5=85,x6=90,执行如图所示的程序框图,那么输出的S是()A.1 B.2 C.3 D.4【考点】EF:程序框图.【分析】由模拟程序框图的运行过程,得出输出的S是记录六次数学测试成绩中得分60以上的次数,由数据得出S的值.【解答】解:模拟程序框图的运行过程,知输出的S是记录六次数学测试成绩中得分60以上的次数;∴比较数据:x1=52,x2=70,x3=68,x4=55,x5=85,x6=90,得出S=4;故选:D.4.设a,b是不同的直线,α,β是不同的平面,则下列四个命题中错误的是()A.若a⊥b,a⊥α,b⊄α,则b∥αB.若a∥α,a⊥β,则α⊥βC.若a⊥β,α⊥β,则a∥αD.若a⊥b,a⊥α,b⊥β,则α⊥β【考点】LP:空间中直线与平面之间的位置关系.【分析】在A中,由线面垂直的性质定理得b∥α;在B中,面面垂直的判定定理得α⊥β;在C中,a∥α或a⊂α;在D中,由面面垂直的判定定理得α⊥β.【解答】解:由a,b是不同的直线,α,β是不同的平面,知:在A中,若a⊥b,a⊥α,b⊄α,则由线面垂直的性质定理得b∥α,故A正确;在B中,若a∥α,a⊥β,则面面垂直的判定定理得α⊥β,故B正确;在C中,若a⊥β,α⊥β,则a∥α或a⊂α,故C错误;在D中,若a⊥b,a⊥α,b⊥β,则由面面垂直的判定定理得α⊥β,故D正确.故选:C.5.已知x,y满足,若存在x,y使得2x+y≤a成立,则a的取值范围是()A.(2,+∞)B.[2,+∞)C.[4,+∞)D.[10,+∞)【考点】7C:简单线性规划.【分析】画出x,y满足的平面区域,求出可行域各角点的坐标,然后利用角点法,求出目标函数的最大值和最小值,即可得到a的取值范围.【解答】解:令z=2x+y,画出x,y满足,的可行域,由可行域知:目标函数过点A时取最大值,由,可得x=3,y=4,可得A(3,4)时,z的最大值为:10.所以要使2x+y≤a恒成立,只需使目标函数的最大值小于等于a 即可,所以a的取值范围为a≥10.故答案为:a≥10.故选:D.6.某几何体的三视图如图所示,则该几何体的体积为()A.4 B.2 C.6 D.【考点】L!:由三视图求面积、体积.【分析】由三视图还原原几何体,该几何体为四棱锥,底面ABCD为直角梯形,AB∥CD,AB ⊥BC,PC⊥平面ABCD.然后由棱锥体积公式得答案.【解答】解:由三视图还原原几何体如图:该几何体为四棱锥,底面ABCD为直角梯形,AB∥CD,AB⊥BC,PC⊥平面ABCD.∴该几何体的体积V=.故选:B.7.数列{a n}满足a n+1(a n﹣1﹣a n)=a n﹣1(a n﹣a n+1),若a1=2,a2=1,则a20=()A. B.C.D.【考点】8H:数列递推式.【分析】数列{a n}满足a n+1(a n﹣1﹣a n)=a n﹣1(a n﹣a n+1),展开化为: +=.利用等差数列的通项公式得出.【解答】解:数列{a n}满足a n+1(a n﹣1﹣a n)=a n﹣1(a n﹣a n+1),展开化为: +=.∴数列是等差数列,公差为=,首项为1.∴=1+=,解得a20=.故选:C.8.长为的线段AB在双曲线x2﹣y2=1的一条渐近线上移动,C为抛物线y=﹣x2﹣2上的点,则△ABC面积的最小值是()A.B.C.D.7【考点】KC:双曲线的简单性质.【分析】求出双曲线的渐近线方程,设C(m,﹣m2﹣2),运用点到直线的距离公式,以及二次函数的最值的求法,再由三角形的面积公式,即可得到三角形的面积的最小值.【解答】解:双曲线x2﹣y2=1的一条渐近线方程为y=x,C为抛物线y=﹣x2﹣2上的点,设C(m,﹣m2﹣2),C到直线y=x的距离为d==≥,当m=﹣时,d的最小值为,可得△ABC的面积的最小值为S=×4×=.故选:A.9.已知圆x2+y2=4的动弦AB恒过点(1,1),若弦长AB为整数,则直线AB的条数是()A.2 B.3 C.4 D.5【考点】J9:直线与圆的位置关系.【分析】圆x2+y2=4的圆心O(0,0),半径r=2,点(1,1)与圆心O(0,0)的距离d=,从而弦长AB的可能取值为2,3,4,且弦AB过点(1,1),由此能求出直线AB的条数.【解答】解:圆x2+y2=4的圆心O(0,0),半径r=2,圆x2+y2=4的动弦AB恒过点(1,1),点(1,1)与圆心O(0,0)的距离d==,∴弦长AB的可能取值为2,3,4,且弦AB过点(1,1),∴直线AB的条数是3条.故选:B.10.将函数的图象向右平移θ(θ>0)个单位长度后关于y轴对称,则θ的最小值是()A.B.C.D.【考点】GL:三角函数中的恒等变换应用;HJ:函数y=Asin(ωx+φ)的图象变换.【分析】将函数f(x)化简,根据三角函数的平移变换规律即可求解.【解答】解:函数=sin(x+),图象向右平移θ(θ>0)个单位长度后,可得sin(x﹣θ+),关于y轴对称,∴,k∈Z.即θ=﹣∵θ>0,当k=﹣1时,可得θ的最小值为,故选:D.11.已知三棱锥S﹣ABC的底面△ABC为正三角形,顶点在底面上的射影为底面的中心,M,N分别是棱SC,BC的中点,且MN⊥AM,若侧棱,则三棱锥S﹣ABC的外接球的表面积是()A.12π B.32π C.36π D.48π【考点】LG:球的体积和表面积.【分析】由题意推出MN⊥平面SAC,即SB⊥平面SAC,∠ASB=∠BSC=∠ASC=90°,将此三棱锥补成正方体,则它们有相同的外接球,正方体的对角线就是球的直径,求出直径即可求出球的表面积积.【解答】解:∵M,N分别为棱SC,BC的中点,∴MN∥SB∵三棱锥S﹣ABC为正棱锥,∴SB⊥AC(对棱互相垂直),∴MN⊥AC又∵MN⊥AM,而AM∩AC=A,∴MN⊥平面SAC,∴SB⊥平面SAC∴∠ASB=∠BSC=∠ASC=90°以SA,SB,SC为从同一定点S出发的正方体三条棱,将此三棱锥补成以正方体,则它们有相同的外接球,正方体的对角线就是球的直径.∴2R=SA=6,∴R=3,∴S=4πR2=36π.故选:C12.若函数f(x)=xlnx﹣ax2有两个极值点,则实数a的取值范围是()A. B. C.(1,2)D.(2,e)【考点】6D:利用导数研究函数的极值.【分析】f(x)=xlnx﹣ax2(x>0),f′(x)=lnx+1﹣2ax.令g(x)=lnx+1﹣2ax,由于函数f(x)=x(lnx﹣ax)有两个极值点⇔g(x)=0在区间(0,+∞)上有两个实数根.求出g(x)的导数,当a≤0时,直接验证;当a>0时,利用导数研究函数g(x)的单调性可得,要使g(x)有两个不同解,只需要g()=ln>0,解得即可.【解答】解:f(x)=xlnx﹣ax2(x>0),f′(x)=lnx+1﹣2ax.令g(x)=lnx+1﹣2ax,∵函数f(x)=x(lnx﹣ax)有两个极值点,则g(x)=0在区间(0,+∞)上有两个实数根.g′(x)=﹣2a=,当a≤0时,g′(x)>0,则函数g(x)在区间(0,+∞)单调递增,因此g(x)=0在区间(0,+∞)上不可能有两个实数根,应舍去.当a>0时,令g′(x)=0,解得x=,令g′(x)>0,解得0<x<,此时函数g(x)单调递增;令g′(x)<0,解得x>,此时函数g(x)单调递减.∴当x=时,函数g(x)取得极大值.当x趋近于0与x趋近于+∞时,g(x)→﹣∞,要使g(x)=0在区间(0,+∞)上有两个实数根,则g()=ln>0,解得0<a<.∴实数a的取值范围是(0,).故选:A.二、填空题:本大题共4小题,每小题5分,共20分.13.已知=(﹣2,2),=(1,0),若向量=(1,﹣2)使﹣λ共线,则λ=﹣1 .【考点】9R:平面向量数量积的运算.【分析】由已知向量的坐标求得﹣λ的坐标,再由向量关系的坐标运算列式求解.【解答】解:∵ =(﹣2,2),=(1,0),∴﹣λ=(﹣2,2)﹣λ(1,0)=(﹣2﹣λ,2),由向量=(1,﹣2)与﹣λ共线,得1×2+2×(﹣2﹣λ)=0.解得:λ=﹣1.故答案为:﹣1.14.一组数据1,10,5,2,x,2,且2<x<5,若该数据的众数是中位数的倍,则该数据的方差为9 .【考点】BB:众数、中位数、平均数.【分析】根据题意求出该组数据的众数和中位数,得出x的值,再计算平均数和方差.【解答】解:根据题意知,该组数据的众数是2,则中位数是2÷=3,把这组数据从小到大排列为1,2,2,x,5,10,则=3,解得x=4,所以这组数据的平均数为=×(1+2+2+4+5+10)=4,方差为S2=×[(1﹣4)2+(2﹣4)2×2+(4﹣4)2+(5﹣4)2+(10﹣4)2]=9.故答案为:9.15.非零实数a,b满足tanx=x,且a2≠b2,则(a﹣b)sin(a+b)﹣(a+b)sin(a﹣b)= 0 .【考点】HP:正弦定理;HR:余弦定理.【分析】由已知可得b=tanb,a=tana,利用两角和与差的正弦函数公式化简所求可得2acosasinb﹣2bsinacosb,利用同角三角函数基本关系式化简即可得解.【解答】解:∵非零实数a,b满足tanx=x,且a2≠b2,∴可得:b=tanb,a=tana,∴原式=(a﹣b)(sinacosb+cosasinb)﹣(a+b)(sinacosb﹣cosasinb)=2acosasinb﹣2bsinacosb=2tanacosasinb﹣2tanbsinacosb=2sinasinb﹣2sinasinb=0.故答案为:0.16.已知椭圆的左、右焦点分别为F1,F2,左右顶点分别为A1,A2,P为椭圆上任意一点(不包括椭圆的顶点),则以线段PF i(i=1,2)为直径的圆与以A1A2为直径的圆的位置关系为内切.【考点】K4:椭圆的简单性质.【分析】设PF1的中点为M,可得以线段PF i(i=1,2)为直径的圆与以A1A2为直径的圆的圆心距为OM,根据中位线的性质得OM==a﹣,即可【解答】解:如图,设PF1的中点为M,可得以线段PF i(i=1,2)为直径的圆与以A1A2为直径的圆的圆心距为OM,根据中位线的性质得OM==a﹣,a﹣就是两圆的半径之差,故两圆内切.故答案为:内切.三、解答题:本大题共5小题,共70分.解答应写出必要的文字说明或推理、验算过程. 17.已知三角形ABC中,角A,B,C的对边分别为a,b,c,若,且角A 为锐角.(1)求三角形内角A的大小;(2)若a=5,b=8,求c的值.【考点】HT:三角形中的几何计算.【分析】(1)根据化简,即可求解A的大小;(2)a=5,b=8,利用余弦定理即可求解c的值.【解答】解:(1)由题意,,即tan2A=.∴2A=或者2A=,∵角A为锐角,∴A=.(2)由(1)可知A=,a=5,b=8;由余弦定理,2bccosA=c2+b2﹣a2,可得:,解得:c=或者.18.如图,ABC﹣A'B'C'为直三棱柱,M为CC的中点,N为AB的中点,AA'=BC=3,AB=2,AC=.(1)求证:CN∥平面AB'M;(2)求三棱锥B'﹣AMN的体积.【考点】LF:棱柱、棱锥、棱台的体积;LS:直线与平面平行的判定.【分析】(1)取A′B′的中点E,连接EC′,EN,由已知可得AB′,EN共面,设AB′∩EN=F,连接FM,可得NF∥CM,NF=CM,从而得到CN∥FM,然后利用线面平行的判定可得CN∥平面AB'M;(2)由CM∥平面ABB′,可得M到平面ANB′的距离等于C到平面ANB′的距离,则V M﹣ANB′=V C,证得BC⊥平面ABB′A′,则三棱锥B'﹣AMN的体积可求.﹣ANB′【解答】(1)证明:如图,取A′B′的中点E,连接EC′,EN,∵ABC﹣A′B′C′为直三棱柱,∴ABB′A′为矩形,则AB′,EN共面,设AB′∩EN=F,连接FM,则EN∥BB′∥CC′,且F为AB′的中点.又∵M为CC′的中点,∴NF∥CM,NF=CM,则CN∥FM,而MF⊂平面AB'M,CN⊄平面AB'M,∴CN∥平面AB'M;(2)解:∵CM∥平面ABB′,∴M到平面ANB′的距离等于C到平面ANB′的距离,∴V M﹣ANB′=V C﹣ANB′∵ABB′A′为矩形,N为AB中点,∴.∵ABC﹣A'B'C'为直三棱柱,∴平面ABC⊥平面ABB′A′,且平面ABC∩平面ABB′A′=AB,在三角形ABC中,AB2+BC2=AC2,∴AB⊥BC,即BC⊥平面ABB′A′,∴.19.为考查某种疫苗的效果,进行动物实验,得到如下疫苗效果的实验列联表:感染未感染总计没服用 20 50服用 40总计 100(1)请完成上面的列联表,并回答是否有97.5%的把握认为这种疫苗有效?并说明理由;(2)利用分层抽样的方法在感染的动物中抽取6只,然后在所抽取的6只动物中任取2只,问至少有1只服用疫苗的概率是多少?参考公式:K2=参考数值:P(K2≥k0) 0.05 0.025 0.010 k0 3.841 5.024 6.635【考点】BO:独立性检验的应用;CC:列举法计算基本事件数及事件发生的概率.【分析】(1)根据题意填写列联表,计算K2,对照临界值得出结论;(2)利用分层抽样原理以及列举法计算基本事件数,求出对应的概率值.【解答】解:(1)根据题意,填写列联表如下:感染未感染总计没服用 20 30 50服用 10 40 50总计 30 70 100根据表中数据,计算K2==≈4.76<5.024,所以没有97.5%的把握认为这种疫苗有效;(2)利用分层抽样法抽取的6只中有4只没服用疫苗,2只服用疫苗,记4只没服用疫苗的为1,2,3,4,2只服用疫苗的为A、B;从这6只中任取2只,基本事件是12、13、14、1A、1B、23、24、2A、2B、34、3A、3B、4A、4B、AB共15种,至少有1只服用疫苗的基本事件是1A、1B、2A、2B、3A、3B、4A、4B、AB共9种,故所求的概率是=.20.一张坐标纸上涂着圆E:(x+1)2+y2=8及点P(1,0),折叠此纸片,使P与圆周上某点P'重合,每次折叠都会留下折痕,设折痕与EP'的交点为M.(1)求M的轨迹C的方程;(2)直线l:y=kx+m与C的两个不同交点为A,B,且l与以EP为直径的圆相切,若,求△ABO的面积的取值范围.【考点】J9:直线与圆的位置关系.【分析】(1)折痕为PP′的垂直平分线,则|MP|=|MP′|,推导出E的轨迹是以E、P为焦点的椭圆,且a=,c=1,由此能求出M的轨迹C的方程.(2)l与以EP为直径的圆x2+y2=1相切,从而m2=k2+1,由,得(1+2k2)x2+4kmx+2m2﹣2=0,由此利用根的判别式、韦达定理、向量的数量积、弦长公式、三角形面积公式,能求出△AOB的面积的取值范围.【解答】解:(1)折痕为PP′的垂直平分线,则|MP|=|MP′|,由题意知圆E的半径为2,∴|ME|+|MP|=|ME|+|MP′|=2>|EP|,∴E的轨迹是以E、P为焦点的椭圆,且a=,c=1,∴b2=a2﹣c2=1,∴M的轨迹C的方程为=1.(2)l与以EP为直径的圆x2+y2=1相切,则O到l即直线AB的距离:=1,即m2=k2+1,由,消去y,得(1+2k2)x2+4kmx+2m2﹣2=0,∵直线l与椭圆交于两个不同点,∴△=16k2m2﹣8(1+2k2)(m2﹣1)=8k2>0,k2>0,设A(x1,y1),B(x2,y2),则,,y1y2=(kx1+m)(kx2+m)=k2x1x2+km(x1+x2)+m2=,又=x1x2+y1y2=,∴,∴,==,设μ=k4+k2,则,∴=,,∵S△AOB关于μ在[,2]单调递增,∴,∴△AOB的面积的取值范围是[,].21.已知函数f(x)=mx+2lnx+,m∈R.(1)讨论函数f(x)的单调性;(2)设函数g(x)=,若至少存在一个x0∈[1,e],使得f(x0)>g(x0)成立,求实数m的取值范围.【考点】6E:利用导数求闭区间上函数的最值;6B:利用导数研究函数的单调性.【分析】(1)求出函数的导数,通过讨论m的范围,求出函数的单调区间即可;(2)问题转化为至少存在一个x0∈[1,e],使得m>﹣成立,设H(x)=﹣,根据函数的单调性求出m的范围即可.【解答】解:(1)函数的定义域是(0,+∞),f′(x)=m++=,m=0时,f′(x)=,f(x)在(0,+∞)递增,m>0时,f′(x)=,令f′(x)=0,解得:x=1﹣或x=﹣1,若1﹣>0,即m>2时,x∈(0,1﹣)时,f′(x)<0,x∈(1﹣,+∞)时,f′(x)>0,故f(x)在(1﹣,+∞)递增,在(0,1﹣)递减,若1﹣≤0,即m≤2时,x∈(0,+∞)时,f′(x)>0,f(x)在(0,+∞)递增,m<0时,x∈(0,1﹣)时,f′(x)>0,x∈(1﹣,+∞)时,f′(x)<0,故f(x)在(0,1﹣)递增,在(1﹣,+∞)递减;(2)令h(x)=f(x)﹣g(x)=mx+2lnx﹣,∵至少存在一个x0∈[1,e],使得f(x0)>g(x0)成立,∴至少存在一个x0∈[1,e],使得m>﹣成立,设H(x)=﹣,则H′(x)=﹣2(+),∵x∈[1,e],1﹣lnx>0,∴H′(x)<0,∴H(x)在[1,e]递减,H(x)≥H(e)=∴m>.[选修4-4:参数方程与极坐标系]22.在平面直角坐标系xoy中,以坐标原点O为极点,x轴的正半轴为极轴的极坐标系中,曲线C的极坐标方程为,且曲线C在极坐标系中过点(2,π).(1)求曲线C的直角坐标方程;(2)设直线(t为参数)与曲线C相交于A,B两点,直线m过线段AB 的中点,且倾斜角是直线l的倾斜角的2倍,求m的极坐标方程.【考点】Q4:简单曲线的极坐标方程;QH:参数方程化成普通方程.【分析】(1)由曲线C在极坐标系中过点(2,π),得到曲线C的极坐标方程为4ρ2sin2θ+ρ2cos2θ=4,由此能求出曲线C的直角坐标方程.(2)直线l消去参数t,得直线l的普通方程为x﹣2y+2=0,联立,得x2+2x=0,求出AB的中点为M(﹣1,),从而直线l的斜率为,由此求出直线m的斜率为.从而求出直线m的直角坐标方程,进而求出m的极坐标方程.【解答】解:(1)∵曲线C在极坐标系中过点(2,π),∴把(2,π)代入曲线C的极坐标方程,得:4=,解得a=4,∴曲线C的极坐标方程为,即4ρ2sin2θ+ρ2cos2θ=4,∴曲线C的直角坐标方程为x2+4y2=4,即=1.(2)∵直线(t为参数),∴消去参数t,得直线l的普通方程为x﹣2y+2=0,联立,得x2+2x=0,解得x=﹣2或x=0,∴A(﹣2,0),B(0,1),∴AB的中点为M(﹣1,),∵直线l的斜率为,即tanα=,∴tan2α==.∴直线m的方程为y﹣=(x+1),即8x﹣6y+11=0,∴m的极坐标方程为8ρcosθ﹣6ρsinθ+11=0.[选修4-5:不等式选讲]23.已知函数f(x)=|x﹣1|+|x﹣a|(a>0),其最小值为3.(1)求实数a的值;(2)若关于x的不等式f(x)+|x|>m2﹣2m对于任意的x∈R恒成立,求实数m的取值范围.【考点】R4:绝对值三角不等式;R5:绝对值不等式的解法.【分析】(1)求出f(x)的最小值,得到关于a的方程,求出a的值即可;(2)根据不等式的性质,问题转化为m2﹣2m<3,解出即可.【解答】解:(1)f(x)=|x﹣1|+|x﹣a|≥|a﹣1|,故|a﹣1|=3,解得:a=﹣2或4,由a>0,得a=4;(2)由(1)得f(x)=|x﹣1|+|x﹣4|,x≥4时,f(x)=x﹣1+x﹣4=2x﹣5≥3,1<x<4时,f(x)=x﹣1﹣x+4=3,x≤1时,f(x)=1﹣x﹣x+4=﹣2x+5≥3,∴f(x)+|x|≥3,当x=0时”=“成立,故m2﹣2m<3即(m+1)(m﹣3)<0,解得:﹣1<m<3,故m的范围是(﹣1,3).。
一、阅读理解(每小题2分,共30分)AAbout 30 years ago,I left Cuba for the United States with my son.After getting settled finally in Brunswick,New Jersey,I enrolled(注册) my son in kindergarten.Several weeks later,my son's teacher asked me to meet him at his office. In the teacher's office,an exchange of greetings was followed by his questions:“Is your son mentally retarded(弱智的)? Does he suffer from any kind of mental disability?”Was he talking about my wonderful Scola? No,no,it can't be.What a helpless,lonely moment! I told him that Scola was a quiet,sweet little boy,instead.I asked him why he was asking me all these questions.My son could not follow the teacher's directions, he told me,and thus,Scola was disrupting the class.Didn't he know my son did not speak English yet?He was angry:“Why hasn't your son been taught to speak English? Don't you speak English at home?”No,I didn't speak English at home,I replied.1 was sure my son would learn English in a couple of months,and I didn't want him to forget his native language.Well,wrong answer! What kind of person would not speak in English to her son at home and at all time?“Are you one of those people who come to this country to save dollars and send them back to their country,never wanting to be a part of this society?”Needless to say,I tried to tell him I was not one of“those people”.Then he told me the meeting was over,and I left.As I had expected,my son learned to speak English fluently before the school year was over.He went on to graduate from college and got a job,earning close to sixfigures.He travels widely and leads a well-adjusted,contented life.And he has benefited from being bilingual (双语的).Speaking more than one language allows people to communicate with others;it teaches people about other cultures and other places—something very basic and obviously lacking in the“educator”I met in New Jersey.1.The teacher asked the author to his office____________.A.to discuss Scola's in-class performanceB. to get Scola enrolled in a kindergartenC.to find a language partner for ScolaD. to work out a study plan for Scola2.What does the underlined word“disrupting”in Paragraph 4 probably mean?A.Breaking. B Following.C.Attending.D.Disturbing.3.The author's attitude towards being bilingual may best be described as_____________.A.critical B.casual C.positiveD.passive4.This text is likely to be selected from a book of__________.A.medicine B.education C.geography D.historyBPlanning a visit to the UK? Here we help with ways to cut your costs.AVOID B1G EVENTS Big sporting events.Concerts and exhibitions can increase the cost of accommodation and make it harder to find a room A standard double room at the Thistle Brighton on the final Friday of the Brighton Comedy Festival(19 Oct.) cost £169.15 at Booking.com.A week later,the same room cost £118.15.If you can be flexible and want to know dates to avoid—or you're looking for a big event to pass your time check out sites such as Whatsonwher.com,which allow you to search for events in the UK by city,date and category.STAY AWAY FROM THE STATION If traveling to your destination by train,you may want to find a good base close to the station,but you could end up paying more for the sake of convenience at the start of your holiday.Don't be too choosy about the part of town you stay in.Booking two months in advance,the cheapest room at Travelodge's Central Euston hotel in London for Saturday 22 September was £95.95.A room just a tube journey away at its Covent Garden hotel was £75.75.And at Farringdon,a double room cost just £62.95.LOOK AFTER YOURSELF Really central hotels in cities such as London,Edinburgh and Cardiff can cost a fortune,especially at weekends and during big events.As an alternative consider checking into a self-catering flat with its own kitchen.Often these flats are hidden away on the top floors of city centre buildings.A great example is the historic O'Neill Flat on Edinburgh's Royal Mile,available for £420 for five days in late September,with room for four adults.GET ON A BIKE London's “Boris bikes” have attracted the most attention,but other cities also have similar programmes that let you rent a bicycle and explore at your own pace,saving you on public transport or car parking costs.Among the smaller cities with their own programmes are Newcastle(casual members pay around £1.50 for two hours)and Cardiff(free for up to 30 minutes,or £5 per day).5.The Brighton Comedy Festival is mentioned mainly to show big events may_________.A. help travelers pass time B. attract lots of travelers to the UKC. allow travelers to make flexible plansD.cause travelers to pay more for accommodation6.“Farringdon”in Paragraph 5 is most probably___________.A.a hotel away from the train station B. the tube 1ine to Covent GardenC. an ideal holiday destination D. the name of a travel agency7.The passage shows that the O'N eill Flat__________.A. lies on the ground floor B.is located in central LondonC. provides cooking facilities for touristsD.costs over £100 on average per day in late September8.Cardiff’s program allows a free bike for a maximum period of .A.half an four B.one hour C.one hour and a half D.two hoursCApple SeedsCirculation(发行量):1 Year,9 IssuesCover Price:$44.55Price For You:$33.95Product Description:Apple Seeds is an award winning magazine filled with stories for kids aged from 7 to 9.The cover is very soft,providing durability(耐用性)that allows each issue to be enjoyed for many years to come.Besides,there is a big surprise for you—it's being sold at a more favorable discount than usual.Better LifeCirculation:1 Year,12 IssuesCover Price:$44.55Price For You:$15.00Product Description:Designed for those who have a strong interest in personal lifestyle.Better Life is America's complete home and family service magazine.It offers help with food,recipes,decorating,building,gardening,family health,money management,and education.Humor TimesCirculation:1 Year,12 IssuesCover Price:$36.00Price For You:$11.95Product Description:The Humor Times magazine is for those who love to laugh! Full of cartoons and humor columns,it shows up in your mailbox once a month and keeps you smiling all year round! In today's world,you need a reason to laugh.So let's find it in Humor Times.News ChinaCirculation:1 Year,12 IssuesCover Price:$47.88Price For YOU:$19.99Product Description:The News China magazine is the English edition of China Newsweek.The magazine covers the latest Chinese domestic news in politics,business,society,environment,culture,sports and travels,etc.It is the first comprehensive news magazine for readers interested in China.9.What do we know about Apple Seeds?A.The soft cover enables it to be read and kept long.B.It can be purchased as an award for your children.C.It offers the biggest discount among all the magazines.D. The magazine is going to surprise you for many years.10.Tom wants to beautify his house,so he may choose______________.A.Apple Seeds B.Better Life C.Humor Times D.News China11.What kind of people may buy News China?A.People who have an interest in personal lifestyle of the Chinese.B.People who have a strong sense of humor and love to laugh.C.People who want to enlarge the knowledge of their kids.D.People who are interested in China's politics,business and culture.12.Which magazine may best help relieve your work stress?A.Apple Seeds B.Better Life C.Humor Times D.News ChinaDWe've reached a strange—some would say unusual—point.While fighting world hunger continues to be the matter of vital importance according to a recent report from the World Health Organization (WHO),more people now die from being overweight,or say,from being extremely fat,than from being underweight.It's the good life that's mote likely to kill us these days.Worse,nearly 18 million children under the age of five around the world are estimated to be overweight.What's going on?We really don't have many excuses for our weight problems.The dangers of the problem have been drilled into us by public-health campaigns since 2001 and the message is getting through—up to a point.In the 1970s,Finland,for example,had the highest rate of heart disease in the world and being overweight was its main cause.Not any more.A public-health campaign hasgreatly reduced the number of heart disease deaths by 80 per cent over the past three decades.Maybe that explains why the percentage of people in Finland taking diet pills doubled between 2001 and 2005,and doctors even offer surgery of removing fat inside and change the shape of the body.That has become a sort of fashion.No wonder it ranks as the world's most body-conscious country.We know what we should be doing to lose weight—but actually doing it is another matter.By far the most popular excuse is not taking enough exercise.More than half of us admit we 1ack willpower.Others blame good food.They say:it's just too inviting and it makes them overeat.Still others lay the blame on the Americans,complaining that pounds have piled on thanks to eating too much American-style fast food.Some also blame their parents—their genes.But unfortunately,the parents are wronged because they're normal in shape.or rather slim.It's a similar story around the world,although people are relatively unlikely to have tried to lose weight.Parents are eager to see their kids shape up.Do as I say—not as I do.13.Why does the author think that people have no excuse for being overweight?A.A lot of effective diet pills are available.B.Body image has nothing to do with good food.C.They have been made fully aware of its dangers.D.There are too many overweight people in the world.14.The example of Finland is used to illustrate___________.A.the cause of heart disease B.the fashion of body shapingC.the effectiveness of a campaign D.the history of a body-conscious country15.Which would be the best title for the passage?A.Actions or Excuses?B.Overweight or Underweight?C.Who in a Dilemma.D.No Longer Dying of Hunger.二、七选五(根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。
新野三高2019届高三8月第一次阶段性考试语文试题一、阅读下面的文章,完成1~3题。
(9分)人可以大体分为两类。
一类人惯于对外界的影响(包括别人的思想)起强烈的反应。
一类人则消极被动地接受一切事物。
前一类人甚至在孩提时期就对别人教给自己的一切提出疑问,并往往叛逆传统和习俗。
他们富有好奇心,要自己去探索事物。
第二类人更容易适应生活,而且在其他条件相同的情况下,更能积累正规教育所传授的知识。
后一类人的头脑充满了公认的观点和固定的看法,而反应型的人则具有较少的固定观念,他们的思想更自由、更可变。
当然,并不是每一个人,都可按照这两个极端来划分,从而隶属于某一种,但显然,接近被动型的人是不适于从事研究工作的。
怎样选择有前途的人来从事科学研究工作,或是判断自己是否适宜,这是个难题。
列出一连串所需的品格条件对解决问题并无多大帮助,因为目前还没有一种客观的手段来衡量所列出的特点。
然而,心理学家有一天也许会解决这个问题。
例如,可以设计一种实验,来测验人们日常生活方面的知识。
这可以衡量人们好奇心和观察力的大小,即他“发现”周围环境中事物的成功率,因为生活就是一个不断的发现过程。
还可以设计一些实验,来检验人们概括的能力以及能否提出与已知资料相适应的假说的能力。
也许对科学的热爱可这样来考察:看他们在获知科学上的新发现时是高兴还是相反,据此进行判断。
普通的考试并不足以说明学生研究能力的强弱,因为考试往往有利于积累知识的人,而不利于思想家。
出色的考生并不一定擅长于研究工作,而另一方面,一些著名的科学家则往往在考试上表现得不好。
埃里希完全是靠着考官们的好心而通过医学毕业考试的,因为考官们很有见识,承认他有特殊的才能。
而爱因斯坦则在工艺学校入学考试中不及格。
比起那种不加怀疑地接受全部教学内容的学生,善于思考、勇于批判的学生在积累知识方面很有可能处在不利的地位。
我注意到,在英国许多生物学或非生物科学方面的研究人员都是博物学家或者在青年时期曾是博物学爱好者。
新野三高2021届高三8月第一次阶段性考试数学〔文〕试题一、选择题1、2、3、4、5、以下图中可作为函数y=f(x)的图象的是6、以下函数为偶函数的是〔〕A. y=sinxB. y=x3C. y=exD.y=ln1 2+ x7、函数f(x)=1 123xx-+A. 〔-3,0]B. 〔-3,1]C. (-∞,-3)∪〔-3,0]D. (-∞,-3)∪〔-3,1]8、假设偶函数f〔x〕在(-∞,-1]上是增函数,那么以下关系中成立的是9、偶函数f(x)在区间[0,+∞)上单调增加,那么满足f(2x-1)<f 1 3()的x取值范围是A.⎪⎭⎫⎢⎣⎡32,31B.⎪⎭⎫⎝⎛32,31C.⎪⎭⎫⎢⎣⎡32,21B.⎪⎭⎫⎝⎛32,21二、填空题13、设集合A={-1,1,3},B={a+2,a2+4},A∩B={3},那么实数a的值是__________________14、命题“ax2-2ax-3>0不成立〞是真命题,那么实数a的取值范围是__________________15、函数f(x)=-x2+2(a-1)x+2在〔-∞,4〕上是增函数,那么a的范围是______________16、设y=f(x)是定义在R上的偶函数,满足f(x+1)=-f(x),且在[-1,0]上是增函数,给出以下关于函数y=f(x)的判断:①y=f(x)是周期函数;②y=f(x)的图象关于直线x=1对称;③y=f(x)在[0,1]上是增函数;④12f⎛⎫⎪⎝⎭=0其中正确判断的序号是_________.(把你认为正确的序号都填上)三、解答题17、集合M={x|x〔x-a-1〕<0,x∈R},N={x|x2-2x-3≤0},假设 M∪N=N,务实数a的取值范围。
18、设命题p:实数x满足x2-4ax+3a2<0,其中a<0; 命题q:实数x满足x2+2x-8>0,且¬p 是¬q的必要不充分条件,务实数a的取值范围。
河南省新野三高2015届高三8月第一次阶段性考试数学(文)试题一、选择题1、2、3、4、5、下图中可作为函数y=f(x)的图象的是6、下列函数为偶函数的是()A. y=sinxB. y=x3C. y=e xD.y=ln7、函数f(x)=的定义域为A. (-3,0]B. (-3,1]C. (-∞,-3)∪(-3,0]D. (-∞,-3)∪(-3,1]8、若偶函数f(x)在(-∞,-1]上是增函数,则下列关系中成立的是9、已知偶函数f(x)在区间[0,+∞)上单调增加,则满足f(2x-1)<f的x取值范围是A. B. C. B.二、填空题13、设集合A={-1,1,3},B={a+2,a2+4},A∩B={3},则实数a的值为__________________14、命题“ax2-2ax-3>0不成立”是真命题,则实数a的取值范围是__________________15、函数f(x)=-x2+2(a-1)x+2在(-∞,4)上是增函数,则a的范围是______________16、设y=f(x)是定义在R上的偶函数,满足f(x+1)=-f(x),且在[-1,0]上是增函数,给出下列关于函数y=f(x)的判断:①y=f(x)是周期函数;②y=f(x)的图象关于直线x=1对称;③y=f(x)在[0,1]上是增函数;④=0其中正确判断的序号是_________.(把你认为正确的序号都填上)三、解答题17、已知集合M={x|x(x-a-1)<0,x∈R},N={x|x2-2x-3≤0},若M∪N=N,求实数a的取值范围。
18、设命题p:实数x满足x2-4ax+3a2<0,其中a<0; 命题q:实数x满足x2+2x-8>0,且¬p是¬q的必要不充分条件,求实数a的取值范围。
19、设a是实数,定义在R上的函数(1)若f(x)为奇函数,求a的值(2)证明:对于任意实数a,f(x)是增函数22、已知函数f(x)=其中a是大于0的常数.(1)求函数f(x)的定义域;(2)当a∈(1,4)时,求函数f(x)在[2,+∞)上的最小值;(3)若对任意x∈[2,+∞)恒有f(x)>0,试确定a的取值范围.。
新野三高2020届高三8月第一次阶段性考试数学(文)试题
、选择题
已知集合A = {1*3,5,人9}出={0・备6鳥门2八则Apl 等于
C {1,3.9)
D {1-2,3}
険集合 P =
$ =令严一 则 PQQ= A , m | -
C-彳 M I 用 42} 巴知余仲 仙xSl,条件v :—<h 则P 是 r 咸立的
JT
A.充分不必要条件 U 充寒条件
下列命题为真命题的是
九若 M 为真命題侧PM 为真命题
K ^=5"是"/ —4才一5 = 0”的充分不必要条件
C.命题H 若丁v — 1,则F —2丈—3 A0”的否命题为“若x<~l ,则F-2x-3<0"
D 巳知命题3xGR,使得,+工一1<0,则「扒使得,?+J -1>0
5、下图中可作为函数 y=f(x)的图象的是
(-)
9、已知偶函数f(x)在区间[0,+ g )上单调增加,则满足 f(2x-1)<f 3的x 取值范围是
1、 3、 氐必妥不充分条件
D •既非充分也非必雯条4、
D.y=ln X 1
7、函数 f(x)=
1 2x
1 x 3的定义域为 A. (-3 , 0]
(-3 , 1] 8、若偶函数f (x )在(-g ,-1]上是增函数,
B. (-3,1]
C. (- g ,-3) U( -3 , 0]
D. (- g ,-3) U
则下列关系中成立的是 M2) <fl -1)勺弓)
D£2)
6、下列函数为偶函数的是(
C.y=ex A. y=s inx B.y=x3
1 2 1 2 1 2 1 2
A. 3 3
B. 3 3
C. 2 3 B. 2 3
讥设偶函数中浏任意歩出都有恥剁戶―,且当/卜乳一芋朮咚)=4並则fl(107于
"0 玖击C. -10 D•■需
•]Q(Z>0h
11已廁函数川JT)i兀山=0几则的谊等于
lw: + l(j<0> ・
A.沪—1
B.沪十1 C瓶ao
1吨碱丿⑴立一右血任意*山+呦屮加)+2町©心IM!立側实如艇値昶是
■
A. ( —°°f—-g-) H <一* »C) d—" 冷〉D.10扌)
二、填空题
13、_________________________________________________________________________________ 设集合A={-1,1,3},B={a+2,a2+4},A n B={3},则实数a 的值为 _________________________________________
14、_________________________________________________________________________________ 命题“ ax2-2ax-3>0不成立”是真命题,则实数a的取值范围是______________________________________
15、函数f(x)= —x2+2(a —1)x+2在(4)上是增函数,则a的范围是_________________________
16、设y=f(x)是定义在R上的偶函数,满足f(x+1)=-f(x),且在[-1,0]上是增函数,给出下
列关于函数y=f(x)的判断:①y=f(x)是周期函数;②y=f(x)的图象关于直线x=1对称;③y=f(x)
f 1
在[0,1]上是增函数;④2 =0
其中正确判断的序号是 __________ •(把你认为正确的序号都填上)
三、解答题
17、已知集合M={x|x (x-a-1 ) <0, x€ R},N={x|x2-2x-3 < 0},若M U N=N 求实数a 的取值范
围。
18、设命题p:实数x满足x2-4ax+3a2<0,其中a<0;命题q:实数x满足x2+2x-8>0,且?p 是?q的必要不充分条件,求实数a的取值范围。
19、设a是实数,定义在R上的函数⑴
(1) 若f(x)为奇函数,求a的值
(2) 证明:对于任意实数a, f(x)是增函数
20、已WE1 数 fUW tn 玉(疋Rl 且 fUT-
⑴求函数九川的解析式多
⑴作出函数fl 刃的图象,并指出西数⑱的单谓区间 2K 定义在R 上的増111数尸f ㈤对任寿e y€R 都有恥-刃=呦我刃”
(1)求 f(O)j
G)求证:3龙奇函数;
⑶ 若讹•驹■妙32X )对任意兀"恒成立,求实数X 的取值范围一
(1)求函数f(x)的定义域;
(2) 当a €( 1 , 4)时,求函数f(x)在[2,+ )上的最小值;
(3) 若对任意x € [2,+ a )恒有f(x)>0,试确定a 的取值范围 ig(x 22、已知函数f(x)=
:2),
其中a 是大于0的常数.。