上海市虹口区2019届高三一模数学卷(附详细)

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2019年上海市虹口区高考数学一模试卷

2019年上海市虹口区高考数学一模试卷

2019年上海市虹口区高考数学一模试卷一、填空题1. 计算________.【答案】【考点】极限及其运算【解析】当时,,由则可得解.【解答】=.2. 不等式的解集是________ (用区间表示).【答案】【考点】一元二次不等式的解法【解析】先将移项,然后通分,利用同解变形将不等式化为,利用二次不等式的解法求出解集.【解答】解:不等式同解于:,即,即,解得,所以不等式的解集是.故答案为:.3. 设全集________=________,若________=,________=,则________(________)=________【答案】,,,,,,,,,【考点】交、并、补集的混合运算【解析】可解出,然后进行交集、补集的运算即可.【解答】=;∴=;∴=.4. 设常数________,若函数________________=________+________的反函数的图象经过点,则________=________.【答案】,,,,,,【考点】反函数【解析】反函数图象过,等价于原函数的图象过,代点即可求得.【解答】依题意知:=的图象过,∴=,解得=.5. 若一个球的表面积是,则它的体积是________.【答案】【考点】球的体积和表面积【解析】由球的表面积是,求出球半径为,由此能求出球的体积.【解答】解:设球的半径为,∵球的表面积是,∴,解得,∴球的体积.故答案为:.6. 函数________________=________________的值域为________,.【答案】,,,,[函数的值域及其求法【解析】直接利用对勾函数的单调性即可求解函数的最大与最小值,从而可求值域【解答】由对勾函数的单调性可知,=在上单调递减,在上单调递增∴当=时,函数有最小值,∵=,=当=时,函数有最大值=故函数的值域为7. 二项式的展开式中的常数项为________.【答案】【考点】二项式定理的应用【解析】求出二项式的通项公式,令的幂指数等于,求出的值,即可得到展开式中的常数项.【解答】解:二项式的通项公式为,令,解得.故常数项为,故答案为.8. 双曲线的焦点到渐近线的距离为________.【答案】【考点】双曲线的特性【解析】先由题中条件求出焦点坐标和渐近线方程,再代入点到直线的距离公式即可求出结论.【解答】解:由题得:其焦点坐标为,.渐近线方程为,即,所以焦点到其渐近线的距离.故答案为:.9. 若复数________.(为虚数单位),则的模的最大值为【考点】复数的模二阶行列式的定义【解析】由已知展开二阶行列式,求得复数模,利用倍角公式降幂后求最值.【解答】∵=,∴.10. 已知个实数,,,________,________,________,________依次构成等比数列,若从这个数中任取个,则他们的和为正数的概率为________.【答案】,,,,【考点】古典概型及其概率计算公式【解析】这个实数为,,,,,,,根据概率公式计算即可.【解答】由题意可得,这个实数为,,,,,,,①所选个数均为正数:=,②所选个一正一负:,,,,,,共种,∴,11. 如图,已知半圆________的直径________=,________是等边三角形,若点________是边________(包含端点________)上的动点,点________在弧上,且满足________________,则的最小值为________.【答案】,,,,,,,,,【考点】平面向量数量积的性质及其运算【解析】由题意可得,,结合向量数量积的几何意义可知,当与重合时,在上的投影最短,代入可求【解答】∵,∴,∵半圆的直径=,是等边三角形,且边长为,由题意可得,,由数量积的几何意义可知,当与重合时,在上的投影最短,此时=.12. 若直线________=________与曲线________=________恰有两个公共点,则实数________的取值范围为________.【答案】,,,,,【考点】函数的零点与方程根的关系【解析】=即,观察=与=可得恰有两个公共点的的取值范围为:=【解答】=,即,则=与=恰有两个公共点的的取值范围为:=或,二、选择题已知,则“”是“”的()A.充分非必要条件B.必要非充分条件C.充要条件D.既非充分又非必要条件【答案】A【考点】充分条件、必要条件、充要条件【解析】由得:,再由“”与“”的关系判断即可【解答】由得:,又“”能推出“”又“”不能推出“”即“”是“”的充分非必要条件,关于三个不同平面,,与直线,下列命题中的假命题是()A.若,则内一定存在直线平行于B.若与不垂直,则内一定不存在直线垂直于C.若,,,则D.若,则内所有直线垂直于【答案】D【考点】空间中直线与直线之间的位置关系【解析】根据空间线面位置关系的判定和性质判断或距离说明.【解答】解:对于,假设,则内所有平行于的直线都平行,故正确;对于,假设内存在直线垂直于,则,与题设矛盾,故假设错误,故正确;对于,设,,在内任取一点,作于点,于点,则,,且、不可能共线.又,,∴,.又,,,∴.故正确.对于,假设,则内所有平行于的直线都平行,故错误.故选:.已知函数,函数,若函数恰好有个不同零点,则实数的取值范围是()A.B.C.D.【答案】D【考点】根的存在性及根的个数判断【解析】化函数恰好有个不同零点为函数与函数的图象有两个不同的交点,从而解得.【解答】解:∵,∴,而,作函数与函数的图象如下,,结合选项可知,实数的取值范围是,故选:.已知点是抛物线=的对称轴与准线的交点,点为抛物线的焦点,点在抛物线上,在中,若=,则的最大值为()A. B. C. D.【答案】C【考点】抛物线的性质【解析】设的倾斜角为,则,当取得最大值时,最小,此时直线与抛物线相切,将直线方程代入抛物线方程,=,求得的值,即可求得的最大值.【解答】过(轴上方)作准线的垂线,垂足为,则由抛物线的定义可得=,由=,则中由正弦定理可知:则=,∴=,设的倾斜角为,则,当取得最大值时,最小,此时直线与抛物线相切,设直线的方程为=,则,即=,∴==,∴=,即=,则,则的最大值为,三、解答题在如图所示的圆锥中,底面直径与母线长均为,点是底面直径所对弧的中点,点是母线的中点(1)求该圆锥的侧面积与体积;(2)求异面直线与所成角的大小.【答案】由题意得,=,=,,==,侧取的中点,连接,,则或其补角即为所求,易证面,∴,,,∴,故异面直线与所成角的大小为.【考点】旋转体(圆柱、圆锥、圆台)异面直线及其所成的角【解析】(1)直接利用公式代值求解即可;(2)需取中点,利用化异面直线为共面直线,找到异面直线所成角,求解较易.【解答】由题意得,=,=,,==,侧取的中点,连接,,则或其补角即为所求,易证面,∴,,,∴,故异面直线与所成角的大小为.已知函数=是定义在上的奇函数.(1)求实数的值及函数的值域;(2)若不等式在上恒成立,求实数的取值范围.【答案】由=,解得:=,反之=时,=,=,符合题意,故=,由=,时,,时,,故函数的值域是;=在递增,故,故,故,令=,,则随的增大而增大,最大值是,故实数的取值范围是.【考点】函数奇偶性的性质与判断函数恒成立问题【解析】(1)根据函数的奇偶性求出的值,检验即可;(2)问题转化为,令=,,根据函数的单调性求出的范围即可.【解答】由=,解得:=,反之=时,=,=,符合题意,故=,由=,时,,时,,故函数的值域是;=在递增,故,故,故,令=,,则随的增大而增大,最大值是,故实数的取值范围是.某城市的棚户区改造建筑用地平面示意图如图所示,经过调研、规划确定,棚改规划用地区域近似为圆面,该圆的内接四边形区域是原棚户区建筑用地,测量可知边界==,=.=.(1)求的长以及原棚户区建筑用地的面积;(2)因地理条件限制,边界,不能更变,而边界,可以调整,为了增加棚户区建筑用地的面积,请在弧上设计一点,使得棚户区改造后的新建筑用地(四边形)的面积最大,并求出这个面积的最大值.【答案】四边形中,=,∴=,即,解得,且=;∴=,∴建筑用地的面积为=;设=,=,由余弦定理得=,又==,当且仅当=时,等号成立;,得四边形所以,当且仅当=,即为线段垂直平分线与弧交点时,面积最大,此时为等边三角形,面积最大,最大值为.【考点】函数最值的应用【解析】(1)由圆内接四边形对角互补,利用余弦定理求得的值,再求建筑用地的面积;(2)设=,=,利用余弦定理和基本不等式求得四边形面积的最大值.【解答】四边形中,=,∴=,即,解得,且=;∴=,∴建筑用地的面积为=;设=,=,由余弦定理得=,又==,当且仅当=时,等号成立;得,四边形所以,当且仅当=,即为线段垂直平分线与弧交点时,面积最大,此时为等边三角形,面积最大,最大值为.设椭圆Γ:=,点为其右焦点,过点的直线与椭圆Γ相交于点,.(1)当点在椭圆Γ上运动时,求线段的中点的轨迹方程;(2)如图,点的坐标为,若点是点关于轴的对称点,求证:点,,共线;(3)如图,点是直线=上的任意一点,设直线,,的斜率分别为,,.求证:,,成等差数列.【答案】由椭圆方程可知,设,则,由点在椭圆Γ上,有.∴线段的中点的轨迹方程;证明:当的斜率存在时,设其方程为=,,,将=代入椭圆方程并化简得:=.,.∵.∴=,即,,共线.而当斜率不存在时,由椭圆对称性,,重合,结论显然成立,综上,,,共线;证明:设,,由(2)知,,∴=.故,,成等差数列.【考点】轨迹方程椭圆的离心率【解析】(1)由椭圆方程可知,设,则,把的坐标代入椭圆Γ,即可求得线段的中点的轨迹方程;(2)当的斜率存在时,设其方程为=,与椭圆方程联立,利用根与系数的关系证明=,即,,共线.而当斜率不存在时,由椭圆对称性,,重合,结论显然成立,可得,,共线;(3)设,然后证明=即可证明,,成等差数列.【解答】由椭圆方程可知,设,则,由点在椭圆Γ上,有.∴线段的中点的轨迹方程;证明:当的斜率存在时,设其方程为=,,,将=代入椭圆方程并化简得:=.,.∵.∴=,即,,共线.而当斜率不存在时,由椭圆对称性,,重合,结论显然成立,综上,,,共线;证明:设,,由(2)知,,∴=.故,,成等差数列.对于个实数构成的集合=,记=.已知由个正整数构成的集合=满足:对于任意不大于的正整数,均存在集合的一个子集,使得该子集的所有元素之和等于.(1)求,的值;(2)求证:“,,…,成等差数列”的充要条件是“”(3)若=.求证:的最小值是,并求取最小值时,的最大值.【答案】∵由个正整数构成的集合=满足:对于任意不大于的正整数,均存在集合的一个子集,使得该子集的所有元素之和等于.∴=,=.证明:先证明必要性:∵=,=,,,…,成等差数列,∴=,∴.再证充分性:∵,,,…,为正整数数列,∴=,=,,,…,,∴=,∵,∴=,=,…,,∴,,…,成等差数列.先证明,=,…,,假设存在,且为最小的正整数,由题意,则,∵,∴当时,不能等于集合的任何一个子集的所有元素之和,∴假设不成立,即=,…,成立,∴==,即,∴,∵=,∴=,若时,则当时,集合中不可能有不同元素之和为,∴,即,此时,可构造集合=,∵当时,可以等于集合中若干个不同元素之和,∴当时,可以等于集合中若干个不同元素之和,…∴当时,可以等于集合中若干个不同元素之和,∴当时,可以等于集合中若干个不同元素之和,∴当时,可以等于集合,∴集合=满足题设,∴当取最小值时,的最大值为.【考点】子集与真子集等差数列的性质数列的求和【解析】(1)由题意能求出=,=.(2)先证明必要性:推导出=,从而.再证充分性:推导出=,=,,,…,,从而=,从而,,…,成等差数列.(3)先证明,=,…,,推导出当时,不能等于集合的任何一个子集的所有元素之和,再由反证法求出=,…,成立,从而,,推导出,由此能求出当取最小值时,的最大值为.【解答】∵由个正整数构成的集合=满足:对于任意不大于的正整数,均存在集合的一个子集,使得该子集的所有元素之和等于.∴=,=.证明:先证明必要性:∵=,=,,,…,成等差数列,∴=,∴.再证充分性:∵,,,…,为正整数数列,∴=,=,,,…,,∴=,∵,∴=,=,…,,∴,,…,成等差数列.先证明,=,…,,假设存在,且为最小的正整数,由题意,则,∵,∴当时,不能等于集合的任何一个子集的所有元素之和,∴假设不成立,即=,…,成立,∴==,即,∴,∵=,∴=,若时,则当时,集合中不可能有不同元素之和为,∴,即,此时,可构造集合=,∵当时,可以等于集合中若干个不同元素之和,∴当时,可以等于集合中若干个不同元素之和,…∴当时,可以等于集合中若干个不同元素之和,∴当时,可以等于集合中若干个不同元素之和,∴当时,可以等于集合,∴集合=满足题设,∴当取最小值时,的最大值为.。

上海市虹口区2019-2020学年高考第一次大联考数学试卷含解析

上海市虹口区2019-2020学年高考第一次大联考数学试卷含解析

上海市虹口区2019-2020学年高考第一次大联考数学试卷一、选择题:本题共12小题,每小题5分,共60分。

在每小题给出的四个选项中,只有一项是符合题目要求的。

1.已知水平放置的△ABC 是按“斜二测画法”得到如图所示的直观图,其中B′O′=C′O′=1,A′O′=32,那么原△ABC 的面积是( )A 3B .2C 3D 3【答案】A【解析】【分析】先根据已知求出原△ABC 的高为AO 3△ABC 的面积.【详解】由题图可知原△ABC 的高为AO 3∴S △ABC =12×BC×OA =12×2×33 A 【点睛】本题主要考查斜二测画法的定义和三角形面积的计算,意在考察学生对这些知识的掌握水平和分析推理能力. 2.在空间直角坐标系O xyz -中,四面体OABC 各顶点坐标分别为:22(0,0,0),(0,0,2),3,0,0,3,033O A B C ⎫⎛⎫⎪ ⎪⎭⎝⎭.假设蚂蚁窝在O 点,一只蚂蚁从O 点出发,需要在AB ,AC 上分别任意选择一点留下信息,然后再返回O 点.那么完成这个工作所需要走的最短路径长度是( )A .2B .1121-C 521+D .23【答案】C【解析】【分析】将四面体OABC 沿着OA 劈开,展开后最短路径就是AOO '△的边OO ',在AOO '△中,利用余弦定理即可求解.【详解】将四面体OABC 沿着OA 劈开,展开后如下图所示:最短路径就是AOO '△的边OO '.易求得30OAB O AC '∠=∠=︒,由2AO =,233OB =433AB = 433AC =,22263BC OB OC =+=222cos 2AB AC BC BAC AB AC+-⇒∠=⋅ 161683333444233+-== 由余弦定理知2222cos OO AO AO AO AO OAO ''''=+-⋅⋅∠其中2AO AO '==,()321cos cos 608OAO BAC -'∠=︒+∠=∴2521,521OO OO ''=⇒=+故选:C【点睛】本题考查了余弦定理解三角形,需熟记定理的内容,考查了学生的空间想象能力,属于中档题. 3.已知平行于x 轴的直线分别交曲线2ln 21,21(0)y x y x y =+=-≥于,A B 两点,则4AB 的最小值为( )A .5ln 2+B .5ln 2-C .3ln 2+D .3ln 2-【答案】A【解析】【分析】设直线为1122(0),(,)(,)y a a A x y B x y =>,用a 表示出1x ,2x ,求出4||AB ,令2()2ln f a a a =+-,利用导数求出单调区间和极小值、最小值,即可求出4||AB 的最小值.【详解】解:设直线为1122(0),(,)(,)y a a A x y B x y =>,则1ln 21a x =+,11(ln 1)2x a ∴=-, 而2x 满足2221a x =-,2212a x +∴= 那么()()22211144()4ln 122ln 22a AB x x a a a ⎡⎤+=-=--=+-⎢⎥⎣⎦设2()2ln f a a a =+-,则221()a f a a -'=,函数()f a 在⎛ ⎝⎭上单调递减,在⎫+∞⎪⎪⎝⎭上单调递增,所以minmin 42()25ln 22AB f a f ⎛⎫===+ ⎪ ⎪⎝⎭ 故选:A .【点睛】本题考查导数知识的运用:求单调区间和极值、最值,考查化简整理的运算能力,正确求导确定函数的最小值是关键,属于中档题.4.()()()()()*121311x x x nx n N+++⋅⋅⋅+∈的展开式中x 的一次项系数为( ) A .3n CB .21nC + C .1n n C -D .3112n C + 【答案】B【解析】【分析】根据多项式乘法法则得出x 的一次项系数,然后由等差数列的前n 项和公式和组合数公式得出结论.【详解】由题意展开式中x 的一次项系数为21(1)122n n n n C +++++==L . 故选:B .【点睛】本题考查二项式定理的应用,应用多项式乘法法则可得展开式中某项系数.同时本题考查了组合数公式.5.若复数21z m mi =-+(m R ∈)在复平面内的对应点在直线y x =-上,则z 等于( )A .1+iB .1i -C .1133i --D .1133i -+ 【答案】C【解析】【分析】由题意得210m m -+=,可求得13m =,再根据共轭复数的定义可得选项. 【详解】 由题意得210m m -+=,解得13m =,所以1133z i =-+,所以1133z i =--, 故选:C.【点睛】本题考查复数的几何表示和共轭复数的定义,属于基础题.6.已知抛物线2:4(0)C y px p =>的焦点为F ,过焦点的直线与抛物线分别交于A 、B 两点,与y 轴的正半轴交于点S ,与准线l 交于点T ,且||2||FA AS =,则||||FB TS =( ) A .25 B .2 C .72D .3 【答案】B【解析】【分析】过点A 作准线的垂线,垂足为M ,与y 轴交于点N ,由2FA AS =和抛物线的定义可求得TS ,利用抛物线的性质1122AF BF p+=可构造方程求得BF ,进而求得结果. 【详解】 过点A 作准线的垂线,垂足为M ,AM 与y 轴交于点N ,由抛物线解析式知:(),0F p ,准线方程为x p =-.2FA AS =Q ,13SA SF ∴=,133p AN OF ∴==,43AM p ∴=, 由抛物线定义知:43AF AM p ==,1223AS AF p ∴==,2SF p ∴=, 2TS SF p ∴==.由抛物线性质11212AF BF p p +==得:3114p BF p+=,解得:4BF p =, 422FB p TS p∴==. 故选:B .【点睛】本题考查抛物线定义与几何性质的应用,关键是熟练掌握抛物线的定义和焦半径所满足的等式. 7.若a R ∈,则“3a =”是“()51x ax +的展开式中3x 项的系数为90”的( )A .必要不充分条件B .充分不必要条件C .充要条件D .既不充分也不必要条件 【答案】B【解析】【分析】求得()51x ax +的二项展开式的通项为15C k k k a x +⨯⋅,令2k =时,可得3x 项的系数为90,即25290C =a ⨯,求得a ,即可得出结果.【详解】若3a =则()()55=113x ax x x ++二项展开式的通项为+15C 3k k k x ⨯⋅,令13k +=,即2k =,则3x 项的系数为252C 3=90⨯,充分性成立;当()51x ax +的展开式中3x 项的系数为90,则有25290C =a ⨯,从而3a =±,必要性不成立.故选:B.【点睛】本题考查二项式定理、充分条件、必要条件及充要条件的判断知识,考查考生的分析问题的能力和计算能力,难度较易.8.已知等比数列{}n a 满足13a =,13521a a a ++=,则357a a a ++=( )A .21B .42C .63D .84【答案】B【解析】由a 1+a 3+a 5=21得242421(1)21172a q q q q q ++=∴++=∴=∴a 3+a 5+a 7=2135()22142q a a a ++=⨯=,选B.9.在平面直角坐标系中,经过点P ,渐近线方程为y =的双曲线的标准方程为( )A .22142-=x y B .221714x y -= C .22136x y -= D .221147y x -=【答案】B【解析】【分析】 根据所求双曲线的渐近线方程为y 2x =±,可设所求双曲线的标准方程为222x y-=k .再把点()22,2-代入,求得 k 的值,可得要求的双曲线的方程. 【详解】∵双曲线的渐近线方程为y 2x,=±∴设所求双曲线的标准方程为222x y -=k .又()22,2-在双曲线上,则k=16-2=14,即双曲线的方程为222x y 14-=,∴双曲线的标准方程为22x y 1714-= 故选:B【点睛】本题主要考查用待定系数法求双曲线的方程,双曲线的定义和标准方程,以及双曲线的简单性质的应用,属于基础题.10.若x 、y 满足约束条件220100x y x y y --≤⎧⎪-+≥⎨⎪≤⎩,则32z x y =+的最大值为( )A .5B .9C .6D .12【答案】C【解析】【分析】作出不等式组所表示的可行域,平移直线32z x y =+,找出直线在y 轴上的截距最大时对应的最优解,代入目标函数计算即可.【详解】 作出满足约束条件220100x y x y y --≤⎧⎪-+≥⎨⎪≤⎩的可行域如图阴影部分(包括边界)所示.由32z x y =+,得322z y x =-+,平移直线322z y x =-+,当直线322z y x =-+经过点()2,0时,该直线在y 轴上的截距最大,此时z 取最大值,即max 32206z =⨯+⨯=.故选:C.【点睛】本题考查简单的线性规划问题,考查线性目标函数的最值,一般利用平移直线的方法找到最优解,考查数形结合思想的应用,属于基础题.11.音乐,是用声音来展现美,给人以听觉上的享受,熔铸人们的美学趣味.著名数学家傅立叶研究了乐声的本质,他证明了所有的乐声都能用数学表达式来描述,它们是一些形如sin a bx 的简单正弦函数的和,其中频率最低的一项是基本音,其余的为泛音.由乐声的数学表达式可知,所有泛音的频率都是基本音频率的整数倍,称为基本音的谐波.下列函数中不能与函数0.06sin180000y t =构成乐音的是( ) A .0.02sin 360000y t =B .0.03sin180000y t =C .0.02sin181800y t =D .0.05sin 540000y t = 【答案】C【解析】【分析】由基本音的谐波的定义可得12()f nf n *=∈N ,利用12f T ωπ==可得12()n n ωω*=∈N ,即可判断选项. 【详解】由题,所有泛音的频率都是基本音频率的整数倍,称为基本音的谐波, 由12f T ωπ==,可知若12()f nf n *=∈N ,则必有12()n n ωω*=∈N , 故选:C【点睛】本题考查三角函数的周期与频率,考查理解分析能力.12.设n S 为等差数列{}n a 的前n 项和,若33a =-,77S =-,则n S 的最小值为( )A .12-B .15-C .16-D .18-【答案】C【解析】【分析】根据已知条件求得等差数列{}n a 的通项公式,判断出n S 最小时n 的值,由此求得n S 的最小值.【详解】依题意11237217a d a d +=-⎧⎨+=-⎩,解得17,2a d =-=,所以29n a n =-.由290n a n =-≤解得92n ≤,所以前n 项和中,前4项的和最小,且4146281216S a d =+=-+=-.故选:C【点睛】本小题主要考查等差数列通项公式和前n 项和公式的基本量计算,考查等差数列前n 项和最值的求法,属于基础题.二、填空题:本题共4小题,每小题5分,共20分。

2019年上海市虹口区高考数学一模试卷及解析〔精品解析版〕

2019年上海市虹口区高考数学一模试卷及解析〔精品解析版〕

取 2 个,则他们的和为正数的概率为

11.(5 分)如图,已知半圆 O 的直径 AB=4,△OAC 是等边三角形,若点 P 是边 AC(包
含端点 AC)上的动点,点 Q 在弧 上,且满足 OQ⊥OP,则
的ቤተ መጻሕፍቲ ባይዱ小值为

12.(5 分)若直线 y=kx 与曲线 y=2
﹣|x﹣1|恰有两个公共点,则实数 k 的取
20.(16 分)设椭圆Γ: +y2=1,点 F 为其右焦点,过点 F 的直线与椭圆Γ相交于点 P, Q. (1)当点 P 在椭圆Γ上运动时,求线段 FP 的中点 M 的轨迹方程; (2)如图 1,点 R 的坐标为(2,0),若点 S 是点 P 关于 x 轴的对称点,求证:点 Q,S, R 共线; (3)如图 2,点 T 是直线 l:x=2 上的任意一点,设直线 PT,FT,QT 的斜率分别为 kPT, kFT,kQT.求证:kPT,kFT,kQT 成等差数列.
值范围为

二、选择题
13.(5 分)已知 x∈R,则“|x﹣ | ”是“x<1”的( )
第 1 页(共 19 页)
A.充分非必要条件
B.必要非充分条件
C.充要条件
D.既非充分又非必要条件
14.(5 分)关于三个不同平面 α,β,γ 与直线 l,下列命题中的假命题是( )
A.若 α⊥β,则 α 内一定存在直线平行于 β
A.
B.
C.
D.
三、解答题 17.(14 分)在如图所示的圆锥中,底面直径与母线长均为 4,点 C 是底面直径 AB 所对弧
的中点,点 D 是母线 PA 的中点 (1)求该圆锥的侧面积与体积; (2)求异面直线 AB 与 CD 所成角的大小.

上海市虹口区2019届高三一模数学卷word版(附详细答案)

上海市虹口区2019届高三一模数学卷word版(附详细答案)

(第11题图)虹口区2018学年度第一学期教学质量监控测试1.计算153lim ________.54n nnnn +→+∞-=+ 2. 不等式21xx >-的解集为_________. 3.设全集{}{}3,2,1,0,1,2log (1),U R A B x y x ==--==-若,则()U A B =I ð_______. 4. 设常数,a R ∈若函数()()3log f x x a =+的反函数的图像经过点()2,1,则a =_______. 5. 若一个球的表面积为4,π 则它的体积为________. 6. 函数8()f x x x=+[)(2,8)x ∈的值域为________. 7.二项式62x ⎫⎪⎭的展开式的常数项为________.8. 双曲线22143x y -=的焦点到其渐近线的距离为_________.9. 若复数z =sin 1cos i iθθ-(i 为虚数单位),则z 的模的最大值为_________. 10.已知7个实数1,2,4,,,,a b c d -依次构成等比数列,若从这7个数中任取2个,则它们的和为正数的概率为__________.11.如图,已知半圆O 的直径4,AB = OAC ∆是 等边三角形,若点P 是边AC (包含端点,A C )上的动点,点Q 在弧»BC 上,且满足,OQ OP ⊥ 则OP BQ ⋅uur uu u r的最小值为__________.12.若直线y k x =与曲线2log (2)21x y x +=--恰有两个公共点,则实数k 的取值范围为________.二、选择题(本大题共4题,满分20分)每题有且只有一个正确答案,考生应在答题纸的相应题号上,将所选答案的代号涂黑,选对得 5分,否则一律零分. 13.已知,x R ∈则“1233x -<”是“1x <”的 ( )(A )充分非必要条件 (B )必要非充分条件 (C )充要条件 (D )既非充分又非必要条件14.关于三个不同平面,,αβγ与直线l ,下列命题中的假命题是 ( )(第17题图)(A )若,αβ⊥则α内一定存在直线平行于β(B )若αβ与不垂直,则α内一定不存在直线垂直于β (C )若,,l αγβγαβ⊥⊥⋂=, 则l γ⊥ (D )若,αβ⊥则α内所有直线垂直于β15.已知函数21,1,()1,(),11,1,1,x f x a x x g x x x x -≤-⎧⎪=-+=-<<⎨⎪≥⎩若函数()()y f x g x =-恰有两个零点,则实数a 的取值范围为 ( )(A )(0,)+∞ (B )(,0)(0,1)-∞⋃ (C )1(,)(1,)2-∞-⋃+∞ (D )(,0)(0,2)-∞⋃16.已知点E 是抛物线2:2(0)C y p x p =>的对称轴与准线的交点,点F 为抛物线C 的 焦点,点P 在抛物线C 上.在EFP ∆中,若sin sin EFP FEP μ∠=⋅∠,则μ的最大值为()(A(B(C(D 三、解答题(本大题共5题,满分76分)解答下列各题必须在答题纸的规定区域内写出必要的步骤.17.(本题满分14分) 本题共2小题,第1小题6分,第2小题8分. 在如图所示的圆锥中,底面直径与母线长均为4, 点C 是底面直径AB 所对弧的中点,点D 是母线PA 的中点.(1)求该圆锥的侧面积与体积;(2)求异面直线AB 与CD 所成角的大小.18.(本题满分14分)本题共2小题,第1小题6分,第2小题8分.已知函数16()1(0,1)x f x a a a a+=->≠+是定义在R 上的奇函数.(1)求实数a 的值及函数()f x 的值域;(2)若不等式 ()[]331,2x t f x x ⋅≥-∈在上恒成立,求实数t 的取值范围.19.(本题满分14分) 本题共2小题,每小题7分.(第19题图)某城市的棚户区改造建筑用地平面示意图如图所示,经过调研、规划确定,棚改规划用地区域近似为圆面,该圆的内接四边形ABCD 区域是原棚户区建筑用地,测量可知边界2()3(),1().AB AD k m BC k m CD k m ====,(1) 求AC 的长及原棚户区建筑用地ABCD 的面积; (2)因地理条件限制,边界,AD DC 不能变更,而 边界,AB BC 可以调整,为了增加棚户区建筑用地的面积,请在弧 ¼ABC 上设计一点,P 使得棚户区改造后的 新建筑用地(四边形APCD )的面积最大,并求出这 个面积最大值.20.(本题满分16分)本题共3小题,第1小题5分,第2小题5分,第3小题6分. 设椭圆22:1,2x y Γ+=点F 为其右焦点, 过点F 的直线与椭圆Γ相交于点,.P Q (1) 当点P 在椭圆Γ上运动时,求线段FP 的中点M 的轨迹方程;(2) 如图1,点R 的坐标为(2,0),若点S 是点P 关于x 轴的对称点,求证:点,,Q S R 共线;(3) 如图2,点T 是直线:2l x =上的任意一点,设直线,,PT FT QT 的斜率分别为,PT k,,FT QT k k 求证:,,PT FT QT k k k 成等差数列;21.(本题满分18分) 本题共3小题,第1小题4分,第2小题6分,第3小题8分.对于()n n N *∈个实数构成的集合{}12,,,n E e e e =L ,记12E n S e e e =+++L .已知由n 个正整数构成的集合{}12,,,n A a a a =L 12(,3)n a a a n <<<≥L 满足:对于任意不大于A S 的正整数,m 均存在集合A 的一个子集,使得该子集的所有元素之和等于.m (1)试求12,a a 的值;(第20题图1)(第20题图2)(第17题图)(2)求证:“12,,,n a a a L 成等差数列”的充要条件是“1(1)2A S n n =+”;(3)若2018A S =, 求证:n 的最小值为11;并求n 取最小值时,n a 的最大值.虹口区2018学年度第一学期期终教学质量监控测试高三数学 参考答案和评分标准 2018年12月一、填空题(本大题满分54分)本大题共12题,第1-6题,每空填对得4分;第7-12题,每空填对得5分. 请直接将结果填写在答题纸相应题号的空格内. 1.5 2.()1,23. {}1,2 4.8 5.43π6. )9⎡⎣ 7. 60 8 10.4711.2 12.(]{},01-∞⋃二、选择题(本大题共4题,每题5分,满分20分)13. A 14. D 15. B 16. C 三、解答题(本大题共5题,满分76分)17.(本题满分14分) 本题共2个小题,第1小题6分,第2小题8分.解:(1)由已知,得圆锥的底面半径为2OA =,高为OP = …… 2分 故该圆锥的侧面积为248S OA PA πππ=⋅⋅=⨯⨯=. …… 4分该圆锥的体积21()3V OA OP π=⋅⋅⋅=. …… 6分 (2)以直线,,OC OB OP 分别为,,x y z 轴,建立空间直角坐标系,则相关点的坐标为(0,2,0)A -,(0,2,0),B(2,0,0),(0,0,(0,C P D -于是(0,4,0),(2,AB CD ==--u u u r u u u r (10)分故cos ,AB CD AB CD AB CD⋅<>===⋅u u u r u u u ru u u r u u u r uu u r u u u r 因此异面直线AB 与CD 所成角的大小为…… 14分 18.(本题满分14分)本题共2小题,第1小题6分,第2小题8分. 解:(1)由()f x 是R 上的奇函数,知(0)0,f =610, 3.a a a-==+解得(第19题图)此时31(),31x x f x -=+故对于任意的3131,()()0,3131x x x x x R f x f x ----∈+-=+=++有即()f x 是R 上的奇函数;因此实数a 的值为3. …… 4分令31(),31x x f x y -==+则130,1x yy+=>-解得11,y -<<即函数()f x 的值域为()1,1.-…6分(2)解法1:由(1)知31(),31x x f x -=+于是不等式 ()33xt f x ⋅≥-可化为2(3)(2)3(3)0.x xt t -+⋅+-≤ …… 8分 令[][]33,9(1,2)x u x =∈∈因,则不等式2(2)(3)0u t u t -+⋅+-≤在[]3,9u ∈上恒成立.设2()(2)(3),g u u t u t =-+⋅+- 则()0g u ≤在[]3,9u ∈上恒成立, …… 10分等价于(3)0.(9)0g g ≤⎧⎨≤⎩即0(3)93(2)(3)015.15(9)819(2)(3)022t g t t t g t t t ≥⎧=-++-≤⎧⎪⇔⇔≥⎨⎨=-++-≤≥⎩⎪⎩因此,实数t 的取值范围为15,.2⎡⎫+∞⎪⎢⎣⎭…… 14分 (2)解法2:由(1)知31(),31x x f x -=+当[]1,2x ∈时,()0.f x >于是不等式()33xt f x ⋅≥-可化为()233(33)(31)(31)44(31).313131x x x x xx x xt f x --+--≥===----- …… 10分令[][]312,8(1,2)x v x -=∈∈因,则由函数[]4()2,8v v vϕ=-在上递增知,max 15()(8).2v ϕϕ==故由max ()t v ϕ≥恒成立知,实数t 的取值范围为15,.2⎡⎫+∞⎪⎢⎣⎭…… 14分19.(本题满分14分) 本题共2小题,每小题7分.解:(1)设,AC x =则由余弦定理,得2222222321cos ,cos .223221x x B D +-+-==⋅⋅⋅⋅由四边形ABCD 是圆内接四边形,得180,B D ∠+∠=︒故cos cos 0,B D +=从而2222222232107,223221x x x AC +-+-+=⇔==⋅⋅⋅⋅即……3分从而1cos =60=120.2B B D =⇒∠︒∠︒, ……5分故 11=+23sin 6021sin12022ABC ADC ABCD S S S ∆∆=⋅⋅⋅︒+⋅⋅⋅︒=四边形答:AC (km ),原棚户区建筑用地ABCD 的面积为2)k m . ……7分(2)解法1:由条件及“同弧所对的圆周角相等”得60P B ∠=∠=︒.要使棚户区改造后的新建筑用地APCD 的面积更大,必须使APC ∆的面积最大,即点P 到AC 的距离最大,从而点P 在弦AC 的垂直平分线上,即.PA PC = ……10分于是APC ∆为等边三角形,2()AC = (12)分因此,棚户区改造后的新建筑用地APCD ADC S ∆+==即当APC ∆为等边三角形时,新建筑用地APCD 2).k m ……14分(2)解法2:由条件及“同弧所对的圆周角相等”得60P B ∠=∠=︒.设1,(,0),sin .2APC PA u PC v u v S uv P ∆==>=⋅∠=则 ……9分在APC ∆中,由余弦定理,有222227=2cos ),APC AC u v uv P u v uv uv ∆=+-⋅∠=+-≥==故APC S ∆≤当且仅当u v ==. (12)分因此,棚户区改造后的新建筑用地APCD 面积的最大值为4424ADC S ∆+=+=即当APC ∆为等边三角形时,新建筑用地APCD 2).k m (14)20.(本题满分16分)本题共3小题,第1小题5分,第2小题5分,第3小题6分.解:(1)易知(1,0),F 设11(,),(,),M x y P x y 则由M 为线段FP 的中点,得11111212.022x x x x y y y y +⎧=⎪=-⎧⎪⇒⎨⎨+=⎩⎪=⎪⎩ ……2分 于是,由点11(,)P x y 在椭圆22:12x y Γ+=上,得 22(21)(2)12x y -+=,即点M 的轨迹方程为 22(21)82x y -+=. ……5分证:(2)当过点F 的直线与x 轴重合时,点P 与S 重合,点,Q S 分别为椭圆在x 轴的两个顶点,显然点,,Q S R 共线.当过点F 的直线与x 轴不重合时,设其方程为11221,(,),(,),x m y P x y Q x y =+且则11(,),S x y -由221,1,2x m y x y =+⎧⎪⎨+=⎪⎩得22(2)210m y my ++-=,显然0.∆> 所以 12122221,,22my y y y m m +=-=-++于是 22221111(2,)(1,),(2,)(1,),RQ x y my y RS x y my y =-=-=--=--u u u r u u u r故 22112211,,2121RQ RS y y y y k k x my x my --====---- (8)分所以21121221122()0,11(1)(1)RQ RS y y my y y y k k my my my my -+-=+==----即RQ RS k k =,因此点,,Q S R 共线. (10)(第20题图1)(第20题图2)证:(3)由T是直线:2l x=上的点,可设其坐标为(2,).t当过点F的直线与x轴重合时,有(P Q从而+2,,21PT QT FTtk k t k t====-故2.PT QT FSk k k+= (12)分当过点F的直线与x轴不重合时,其方程为11221,(,),(,),x m y P x y Q x y=+且有11221122,,,212121PT QT FTy t y t y t y t tk k k tx my x my----======-----由(2)知12122221,,22my y y ym m+=-=-++于是121221121221212121222222222()(1)()(1)2(1)()2 11(1)(1)()122(1)24(1)222222(1)122PT QTFTy t y t y t my y t my my y t m y y t k kmy my my my m y y m y ym m t mt t mm m t km m mm m----+---+++ +=+==-----+++-+++++====+-++++即2,PT QT FSk k k+=综合上述,得,,PT FT QTk k k成等差数列.……16分21. (本题满分18分)本题共3小题,第1小题4分,第2小题6分,第3小题8分.解:(1)由条件,知A1S,1.A≤∈必有又12na a a<<<L均为正整数,故1=1.a……2分由条件,知A2S,≤故由AS的定义及12na a a<<<L均为正整数,2,A∈必有于是2=2.a……4分证:(2)必要性由“123,,,,na a a aL成等差数列”及12=1,=2a a得=(1,2,,).ia i i n=L此时{}1,2,3,,1,A n n=-L,满足题设条件;从而12112(1).2A nS a a a n n n=+++=+++=+L L……7分充分性 由条件知12n a a a <<<L ,且它们均为正整数,可得(1,2,,)i a i i n ≥=L ,故 112(1)2A S n n n ≥+++=+L 当且仅当(1,2,,)i a i i n ==L 时,上式等号成立. 于是当1(1)2A S n n =+时,=(1,2,,)i a i i n =L ,从而123,,,,n a a a a L 成等差数列. 因此 “123,,,,n a a a a L 成等差数列”的充要条件是“1(1)2A S n n =+”. ……10分证:(3)由于n 元集合A 的非空子集的个数为21,n-故当10n =时,10211023,-=此时A的非空子集的元素之和最多表示出1023个不同的正整数,m 不符合要求. ……12分而用11个元素的集合{}1,2,4,8,1632641282565121024M =,,,,,,的非空子集的元素之和可以表示2047个正整数:1,232046,2047.L ,,, 因此当2018A S =时,n 的最小值为11. ……14分 当2018A S =,n 取最小值11时,设101210,S a a a =+++L 由题设得10112018,S a += 并且10111.S a +≥事实上,若10111,S a +<则101111112019201821,2S a a a =+<-⇒>由11,a N *∈故111010.a ≥此时101008,S ≤从而1009m =时,其无法用A 的非空子集的元素之和表示,与题意矛盾!于是由10112018,S a +=与10111,S a +≥可得 101111112019201821,2S a a a =+≥-⇒≤故由11,a N *∈得111009.a ≤ ……16分当11=1009a 时,用{}1,2,4,8,163264128256,498,1009A =,,,,的非空子集的元素之和可以表示出1,2,3,…,2017,2018中的每一个数.因此,当2018A S =时,n 的最小值为11,n a 的最大值为1009. ……18分。

【高三一模】2019上海虹口区高三一模(含答案及听力全文)

【高三一模】2019上海虹口区高三一模(含答案及听力全文)

虹口区2019学年度第一学期期终学生学习能力诊断测试高三英语试卷. Listening ComprehensionSection ADirections: In Section A, you will hear ten short conversations between two speakers. At the end of each conversation, a question will be asked about what was said. The conversations and the questions will be spoken only once. After you hear a conversation and the question about it, read the four possible answers on your paper, and decide which one is the best answer to the question you have heard.1. A. Husband and wife. B. Secretary and boss.C. Teacher and student.D. Air hostess and passenger.2. A. On July 18th. B. On July 19th. C. On July 20th. D. On July 21st.3. A. Pastimes. B. Occupations.C. Performance skills.D. Musical instruments.4. A. Do the laundry. B. Make a promise.C. Go to the stadium.D. Clean his bedroom.5. A. He is too tired to move.B.He is willing to lend a hand.C.He suggests dining out tonight.D.He expects Marilyn to cook tonight.6. A. The man is hesitant about the offer.B.The man is not excited about the offer.C.The man is going to be a vice president.D.The man is sure he is qualified for the job.7. A. The woman can't wait to buy an iPhone.B.The woman is eager to see the new iPhone.C.The man doesn't care about the new iPhone.D.The man ordered the woman to buy him an iPhone.8. A. She showed no interest in the exhibition.B.The exhibition is unexpectedly satisfactory.C.She could not find her favourite exhibit anywhere.D.She thought the exhibition could have been better.9. A. Jane is always ready to solve problems.B.The man has already asked a favor of Jane.C.Jane is the last one who can solve the problem.D.She suggests the man should not ask Jane for help.10. A. Ellen is very worried about the reading project.B.Students don't want to spend more time reading.C.V olunteers are supposed to set aside time for reading.D.V olunteers will get free books if they fulfill the schedule.Section BDirections: Tn Section B, you will hear two short passages and one longer conversation, and you will be asked several questionson each of the passages and the conversation. The passages and the conversation will be read twice, but the questions will be spoken only once. When you hear a question, read the four possible answers on your paper and decide which one would be the best answer to the question you have heard.Questions 11 through 13 are based on the following passage.11. A. His childhood dream.B.The fate similar to TqbaPs.C.His experience in Pakistan.D. A sad story of a child slave.12. A. To establish a food company.B.To provide access to clean water.C.To help people get rid of poverty.D.To create impact through education.13. A. Kids should struggle for human rights.B.Kids can make a difference to the world.C.Kids are expecting too much of the world.D.Kids are too young to voice their opinions.Questions 14 through 16 are based on the following passage.14. A. It looks like a van with wings.B.Not enough pilots are available.C.It needs a large space for parking.D.It can,t be reserved on the smartphones.15. A. No model has been announced a success yet.B.The Bell Nexus will be introduced to the public soon.C.Bell is cooperating with Uber in working out models.D.Boeing and Airbus have already developed new models.16. A. Air flight. B. Flight plan. C. Flying cars. D. New helicopters.Questions 17 through 20 are based on the following conversation.17. A. Math. B. Sports. C. Geology. D. Biology.18. A. Because he has to hand in his list of grades first.B.Because he is eager to apply for a student loan first.C.Because he has to decide which major to choose first.D.Because he has to finish some extra work for his teacher.19. A. Robert has to pay fbr his sister's education.B.Robert took different science courses in high school.C.Robert will enter the university next spring semester.D.Robert did well in academic performance in high school.20. A. Job interview. B. Major selection.C.University application.D. Academic background.II.Grammar and VocabularySection ADirections: After reading the passage below, fill in the blanks to make the passage coherent and grammatically correct. For the blanks with a given word, fill in each blank with the proper form of the given word; far the other blanks, use one word that best fits each blank.Innovations that will change the classroomsAmerican schools are going high-tech. Many symbols we still associate with classrooms and learning, like chalkboards, pens, notebooks 一even classrooms (21)一are quickly becoming outdated.As this week marks The Huffington Posfs 10th anniversary, weMltake a look at some products that (22)(introduce) to classrooms in the past decade and have the potential to change the educational landscape in the years (23) (come).1.Remote LearningSome schools are cutting down on snow days, thanks to technology. Rather than giving kids the day off (24) weather conditions are too dangerous for commuting, these schools are asking students to follow classroom lessons online.Although kids (25)(hope) for a snow day may not particularly appreciate these advancements in digital learning, online lessons allow these kids to complete their coursework and still interact with peers. Some students with medical conditions (26)"go" to school via video conferencing or even with the help of robots enabledwith video chat that they can control remotely.2.eBooksDiscovery Education has been replacing traditional textbooks with original "techbooks" for six years. These “techbooks" can also be switched to Spanish or French, Kinney said, (27)allows some parents who don,t speak English to help their kids with their homework.cational GamesTn-class gaming options have evolved to include more educational options. GlassLabcreates educational games that are now being used in more than 6,000 classrooms across the country. Teachers get real-time updates on students9 progress as well as suggestions on (28)subjects they need to spend more time perfecting.The Internet and other digital tools have some drawbacks. They're often distracting, (29) most developments have exciting implications fbr the future. Over the last 10 years, technological innovations have made education more interactive, immediate and (30)(personalize),——and have shown us the potential for more accessible and effective classrooms.Section BDirections: Fill in each blank with a proper word chosen from the box. Each word can be used only once. Note that there is one word more than you need.How do Cigarettes Affect the Body?Cigarettes aren't good fbr us. But how exactly do cigarettes harm us? Let's look at what happens as their ingredients make their way through our bodies, and how we benefit (31)when we finally give up smoking.Inside the airways and lungs, smoke increases the (32)of infections as well as long-lasting diseases. It does this by damaging the tiny hair-like tissueswhich keep the airways clean. That's one of the reasons smoking can lead to oxygen loss and (33)of breath.Within about 10 seconds, the bloodstream carries a stimulant called nicotine to the brain, creating the (34)sensations which make smoking highly addictive. Nicotine and other chemicals from the cigarette, at the same time, cause tightness of blood tubes, restricting blood flow. These effects on blood tubes lead to (35)of blood tube walls, increasing the possibilityof heart attacks and strokes.Many of the chemicals inside cigarettes can activate dangerous (36) ____ in the body's DNA that make cancers form. In fact, about one of every three cancer deaths in the United States is caused by smoking. And it's not just lung cancer. Smoking can cause cancer in multiple tissues and organs, as well as damaged eyesight and (37)bones. It makes it harder fbr women to get pregnant. And in men, it can cause long-term damages of body functions.But for those who quit smoking, there's a huge positive upside with almost (38)and long-lasting physical benefits. A day after ceasing, heart attack risk begins to decrease as blood pressure and heart rates (39). Lungs become healthier after about one month, with less coughing. After ten years, the chances of developing fatal lung cancer go down by 50%, probably because the body's ability to repair DNA is once again restored.There's no point pretending this is all easy to achieve. Quitting can lead to anxiety and depression. But fortunately, such effects are usually (40). Advice and support groups and moderate intensity exercise also help smokers stay cigarette-free. Thafs good news, since quitting puts you and your body on the path back to health.III. Reading ComprehensionSection ADirections: 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. Inc. is checking out of China's fiercely competitive domestic e-commerce market.The company told sellers on Thursday that it would no longer 41its third-party online marketplace or provide seller services on its Chinese website, . 42, domestic companies will no longer be able to sell products to Chinese consumers on its e-commerce platform.The decision marks an end to a long 43by America's e-commerce giants in the Chinese market. The firms entered the Chinese market with great attention in the early 2000s, only to 44in the face of competition from China7s faster-moving Internet giants.Amazon has been in talks to 45its e-commerce business for goods imported into China with a Chinese competitor, NetEase Inc.'s Kaola, in a stock-for-stock transaction(交易),according to a person familiar with the matter. That would remove the Amazon name from 46e-commerce in China. Neither company would confirm the progress or details of those 47, nor would they say if they are continuing.In a written statement, Amazon said it remained 48to China through its global stores, Kindle businesses and web services.Amazon China's president would leave to take on another role within the company, the company said. The China consumer-business team will report 49to the company's global team.When Amazon first entered China in 2004 with the 50of , it was the largest online seller for books, music and video there. Most Chinese consumers were using cash-on-delivery as their top form of 51. Today, Amazon China chiefly caters to customers looking fbr imported international goods such as cosmetics and milk powder and is a(n( 52player in the booming Chinese e-commerce market.Amazon China commanded just 6% of gross market volume in the(纟田分的)cross-border e-commerce market in the fourth quarter of 2018, versus NetEaseKaola's 25% 53and the 32% held by Alibaba Group Holding Ltd.'s Tmall International.Chinese consumers are becoming more fascinatedwith 54brands. In 2011, 85% of Chinese consumers said they would always buy a foreign brand over a domestic one. By 2016, 60% of respondents said they preferred domestic over foreign brands. Shaun Rein, China Market Research's founder, said American e-commerce giants 55obstacles in China because they hadn't offered the products or user experience that consumers were looking for.41. A. assist B.expand C. operate D. tailor42. A. As a result B. By contrast C. For example D. In addition43. A. criticism B. negotiation C. struggle D. resolution44. A. interact B. withdraw C. split D. survive45. A. associate B. combine C.exchange D. supply46. A. time-consuming B. long-suffering C. ever-lasting D. consumer-facing47. A. talks B. businesses C. competitions D. instructions48. A. related B. accustomed C. exposed D. committed49. A. automatically B. directly C. regularly D. secretly50. A. breakdown B. improvement C. purchase D. participation51. A. refund B. payment C. sponsorship D. trade52. A. complicated B. critical C. original D. insignificant53. A. share B. budget C. volume D. maximum54. A. foreign B. luxurious C. domestic D. fashionable55. A. dealt with B. forgot about C. got through D. came acrossSection BDirections: 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 and D. Choose the one that fits best according to the information given in the passage you have just read.(A)People worry that developments in Artificial Intelligence, or A.L, will bring about a point in history when A.I. overtakes human intelligence, leading to an unimaginable revolution in human affairs. Or they wonder whether instead of our controlling artificial intelligence, it will control us.The situation may not arise for hundreds of years to come, but this doesn't mean we have nothing to worry about. On the contrary, The A.T. products that now exist are improving faster than most people realize and promise to fundamentally transform our world, not always fbr the better. They are only tools, not a competing form of intelligence. But they will reshape what work means and how wealth is created.Unlike the Industrial Revolution and the Computer Revolution, the A.I. revolution is not taking certain jobs and replacing them with other jobs. Instead, it is believed to cause a wide-scale elimination of jobs 一mostly lower-paying jobs, but some higher-paying ones, too.This transformation will result in enormous profits fbr the companies that develop A.T., as well as fbr the companies that adoptit. We are thus facing two developments that do not sit easily together: enormous wealth concentrated in relatively few hands and enormous numbers of people out of work. What is to be done?Part of the answer will involve educating or retraining people in tasks A.I. tools aren't good at. Artificial intelligence is poorly suited for jobs involving creativity, planning and "cross-field" thinking. But these skills are typically required by high-paying jobs that may be hard to retrain displaced workers to do. More promisine are lower-paying jobs involving the "people skills" that A.I. lacks: social workers, barmen, doormen —professions requiring human interaction. But how many barmen does a society really need?The solution to the problem of mass unemployment will involve "service jobs of love.^, These are jobs that A.I. cannot do, that society needs and that give people a sense of purpose. Examples include accompanying an older person to visit a doctor, helping at an orphanage and serving as a sponsor at charity organization. The volunteer service jobs of today, hi other words, may turn into the real jobs of the future.Other volunteer jobs may be higher-paying and professional, such as compassionate medical service providers. In all cases, people will be able to choose to work fewer hours than they do now.56.In what aspect is the A.I. revolution different from the Industrial or the Computer revolution?A.The A.I. revolution will finally become one beyond human's control.B. A.I. is believed to lead to a point in history when it takes over human intelligence.C.Higher-paying j obs will take the place of lower-paying ones in the A.I. revolution.D.It may bring about mass unemployment no matter how much employees are paid.57.The underlined word "promising" in paragraph 5 is closest in meaning to.A.promotionalB. demandingC. guaranteedD. potential58.What does the author suggest in the face of the A.I. revolution?A.It is sensible to encourage people to take volunteer jobs.B.People should be instructed to do less demanding jobs.C.The problem ofjob loss can be solved by creating lower-paying jobs.D.Jobs requiring knowledge in different fields are suitable for displaced workers.59.Which of the following may serve as the best title of the passage?A.The A.I. Revolution Creates New Job Opportunities.B.Challenges the A.I. Revolution Brings to Job MarketC. A Double-edged Sword: the A.T. RevolutionD.Interrelationship between A.T. and UnemploymentHearing Aids features advanced third generation digital technology at anunbelievably affordable Price! The HCR3 is packed with the same keytechnologies that all high end digital hearing aids share while leavingout the extra bells and whistles that increase cost and require expensiveadjustments. This helps you hear better, while saving you a lot of money.Your new HearClear HCR3 hearing aids work at a fraction of the costof name-brand hearing aids, and you won !t have to keep changing thebatteries! You will love the comfortable and lightweight Open-fit design.The HCR3 is pre-programmed for most moderate to significant hearinglosses, so you won't need professional appointments to make costlyadjustments. It is shipped directly to you and will help you hear betterright out of the box!You can spend thousands for an expensive hearing aid, or you canspend just $ 249 for a hearing aid that is great for most hearinglosses(only $229 each when you buy a pair). We are so sure you willlove your hearing aids that we offer a 100% Money Back Guarantee -Risk Free if you are not satisfied for any reason. 60. How much will you pay if you want to buy a pair ofHCR3 hearing aids? A. $229 B. $249 C. $458 D. $49861. Which of the following features can be added to the section "HCR3Features”?① Built-in programs for different listening situations. ② Easy access to changing batteries.③ Digital sound processing chip.④ Simple adjustments without professional help. A. ①③ B.①③④C.②③④D.①②③ 62. One reason why buying a pair of hearing aids is recommended is that. A. the HCR3 guarantees 100% refund if bought in pairs.B. it will save consumers up to $20 for a pair of hearing aids.C. humans are pre-programmed to better hear with two ears.D. people can hear triple better in various situations with two hearing aids.(C(For several decades, there has been an extensive and organized campaign intended to generate distrust in science, funded by regulated industries and libertarianthink 口〃如(自 由主义智囊团)whose interests and beliefs are threatened by the findings(B)Advanced Rechargeable Digital Hearing Aid Technology Only $229!* B(*Eachwhen you buy a pair) The new Advanced HearClearHCR3 rechargeable Q-〜 hearing aid combines advanced technology with a low price to provide you with outstanding value. 5 Star Reviews! Outstanding Product! "This product is outstanding. Dad loves it, my mom loves it, and 1 am grateful! Don't believe that you have to spend a lot of money to get a quality hearing aid" -Gilmore 8. HCR3 Features!嗜力 A) MicrophoneB) Program ButtonC) Volume ControlD) USB Charging Port &Rechargeable BatteryE) Advanced DigitalProcessorF} Receiver (Speaker) G)Sound Tube Simple. Affordable*Rechargeable Digital Hearing Aid - For Only $229!*The new HearClear™ HCR3 Rechargeable Digital♦ New Advanced Third Generation American Technology ♦ Easy ON / OFF Button ♦ Automatic Noise Reduction and Feedback Cancellation ♦ 100% Money Back Guarantee Even Better In Pairs! Your brain is designed to use both ears working together. In fact, studies show that you may be able tohear up to 3 times better in noisysituations when using two hearingaids. Buy a pair for the best resultsand maximum savings! ADV ANCEDof modern science. In response, scientists have tended to stress the success of science. After all, scientists have been right about most things, from the structure of the universe to the relativity of time and space.Quoting successes isn't wrong, but for many people it's not persuasive. What is typically declared to be the scientific method—develop a supposition, then design an experiment to test it—isn't what scientists actually do. Science is active so that new methods get invented and old ones get abandoned. The scientific method doesn't always work. False theories can produce true results, so even if an experiment works, it doesn't prove that the theory it was designed to test is true.If there is no identifiable scientific method, then what is the guarantee for trust in science?The answer is the methods by which those claims are evaluated. A scientific claim is never accepted as true until it has gone through a long process of examination by fellow scientists. Until this point, scientific feedback is typically fairly friendly. But the next step is different: once the paper is ready, it is presented to a scientific journal, where things get a whole lot tougher. Editors deliberately send scientific papers to people who are not friends or colleagues of the authors, and the job of the reviewer is to find errors or other inadequacies. We call this process “peer review" because the reviewers are scientific peers but they act in the role of a superior who has both the right and the obligation to find fault. It is only after the reviewers and the editor are satisfied that any problems have been fixed that the paper is accepted for publication and enters the body of "science."Does this process ever go wrong? Of course. Scientists are human. But if we look carefully at historical cases where science went wrong, typically there was no agreement reached by all. Some people argue that we should not trust science because scientists are "always changing their mmds.,, While examples of truly settled science being overturned are far fewer than is sometimes claimed, they do exist. But the beauty of this scientific process is that it explains what might otherwise appear paradoxical^JW W (:that science produces both(新颖T生)and stability. New observations, ideas, interpretations introduce novelty; transformative questioning leads to collective decisions and the stability of scientific knowledge. Scientists do change their minds in the face of new evidence, but this is a strength of science, not a weakness.63.Distrust in science has been found because.A.scientists' citing successes isn't persuasive fbr many people to some extentB.most scientists have tended to lay too much emphasis on the success of scienceC. a wide-ranging and organized campaign has been founded in some industries and think tanksD.someone's benefits and beliefs are endangered by the findings of modern science64.Which of the following statements will the author agree with about a scientific method?A. A scientific method doesn't necessarily take effect because science is changing.B. A scientific method is not right because it isn't what scientists actually do.C. A successful experiment can guarantee the truthfulness of a claim by a scientific method.D.True theories can produce folse results because the scientific method doesn't work.65.What purpose does "peer review" in evaluating a scientific claim mainly serve?A.The scientific claim can be completely accepted by the reviewers in the same field.B.The scientific peers can draw right conclusions by finding its faults or other inadequacies.C.The scientific claim can be published and recognized as true in science.D.The scientific paper can be successfully submitted to a scientific journal.66.It can be inferred from the last paragraph that.A.Not all the claims about the falsehood of well-established science lead to its being overturnedB.It is inevitable that science sometimes goes wrong because it appears paradoxicalC.The beauty of science lies in the paradox of being both novel and stableD.Science is not trustful because scientists always change their mindsSection CDirections: Read the passage carefully. Fill in each blank with a proper sentence given in the box. Each sentence can be used only once. Note that there are two more sentences than you need.Is Multitasking Always Good?Not only do smartphones provide unrestricted access to information, they provide perfect opportunities to multitask. Any activity can be accompanied by music, selfies or social media updates. Of course, some people pick poor times to tweet or text, and lawmakers have stepped in. 67 In Honolulu, it's illegal to text or even look at your phone while crossing the street, and in the Netherlands they've banned texting while biking.68 You need to sei仁regulate. Understanding how the brain multitasks and why we find multitasking so appealing will help you realize the danger of pulling out your phone.Multitasking feels like doing two things at the same time, so it seems the danger lies in asking one mental process to do two unrelated things 一for texting drivers, watching the screen and the road.Twenty states have instituted bans on driving using a hand-held phone while still allowing hands-free calls. Yet hands-free or hand-held makes no difference. 69 The real problem is the switch of attention between the conversation and the road, and that affects performance.People sense this, and when on the phone they drive slower and increase their following distance, but they are for too confident that these measures reduce risks. This overconfidence extends to other activities. A 2015 survey showed that a majority of students who use social media, text or watch TV while studying think that they can still comprehend the material they're studying.People don't multitask merely because they see no harm in it; they see benefits. 70Most people will still choose to multitask. But they should, at the very least, be fully aware of how that choice affects them and the potential consequences for themselves and others. They need to pay attention to how much 一or how little 一they are paying attention.IV. Summary WritingDirections: Read the following passage. Summarize the main idea and the main point(s) of the passage in no more than 60 M^ords. Use your own words as far as possible.71.The Zeigarnik EffectHave you ever found yourself thinking about a partially finished project for school or work when you were trying to focus on other things? Or perhaps you wondered what would happen next in your favorite TV show or film series. If you have, you've experienced the Zeigarnik effect. You tend to remember unfinished tasks better than finished tasks. Knowledge of the Zeigarnik effect can be put into use in everyday life.The effect is especially well suited fbr helping overcome procrastination or delaying an action to a later time. We often put off big tasks that seem overwhelming. However, the Zeigarnik effect suggests that the key to overcoming procrastination is to just get started. The first step could be something small and seemingly insignificant. In fact, it's probably best if ifs something fairly easy.The Zeigarnik effect can be useful fbr students who are studying for an exam. The effect tells us that breaking up study periods can actually improve recall. So instead of cramming for an exam all in one sitting, breaks should be scheduled in which the student focuses on something else. This will cause intrusive(侵入的)thoughts, enabling students to rehearse and consolidate the information that must be remembered, leading to better recall when they take the exam.The Zeigarnik effect also points to reasons why people may experience mental health problems. If an individual leaves important tasks incomplete, the intrusive thoughts that result can lead to stress, anxiety, difficulty sleeping, and emotional distress. Conversely, completing a task can give an individual a sense of accomplishment and lead to a feeling of closure that can improve psychological well-being.The Zeigarnik effect can actually be used to positively impact your work productivity.。

上海市2019年高考数学一模试卷(解析版)

上海市2019年高考数学一模试卷(解析版)

2019年上海市高考数学一模试卷一、填空题(共12小题,1-6每题4分,7-12每题5分,共54分)1.(4分)设集合A={x||x﹣2|<1,x∈R},集合B=Z,则A∩B=.2.(4分)函数y=sin(ωx﹣)(ω>0)的最小正周期是π,则ω=.3.(4分)设i为虚数单位,在复平面上,复数对应的点到原点的距离为.4.(4分)若函数f(x)=log2(x+1)+a的反函数的图象经过点(4,1),则实数a=.5.(4分)已知(a+3b)n展开式中,各项系数的和与各项二项式系数的和之比为64,则n=.6.(4分)甲、乙两人从5门不同的选修课中各选修2门,则甲、乙所选的课程中恰有1门相同的选法有种.7.若圆锥的侧面展开图是半径为2cm,圆心角为270°的扇形,则这个圆锥的体积为cm3.8.若数列{a n}的所有项都是正数,且++…+=n2+3n(n∈N*),则()=.9.如图,在△ABC中,∠B=45°,D是BC边上的一点,AD=5,AC=7,DC=3,则AB的长为.10.有以下命题:①若函数f(x)既是奇函数又是偶函数,则f(x)的值域为{0};②若函数f(x)是偶函数,则f(|x|)=f(x);③若函数f(x)在其定义域内不是单调函数,则f(x)不存在反函数;④若函数f(x)存在反函数f﹣1(x),且f﹣1(x)与f(x)不完全相同,则f(x)与f﹣1(x)图象的公共点必在直线y=x上;其中真命题的序号是.(写出所有真命题的序号)11.设向量=(1,﹣2),=(a,﹣1),=(﹣b,0),其中O为坐标原点,a>0,b>0,若A、B、C三点共线,则+的最小值为.12.如图,已知正三棱柱ABC﹣A1B1C1的底面边长为2cm,高为5cm,一质点自A点出发,沿着三棱柱的侧面绕行两周到达A1点的最短路线的长为cm.二、选择题(共4小题,每小题5分,满分20分)13.“x<2”是“x2<4”的()A.充分非必要条件B.必要非充分条件C.充要条件D.既非充分也非必要条件14.若无穷等差数列{a n}的首项a1<0,公差d>0,{a n}的前n项和为S n,则以下结论中一定正确的是()A.S n单调递增B.S n单调递减C.S n有最小值D.S n有最大值15.给出下列命题:(1)存在实数α使.(2)直线是函数y=sinx图象的一条对称轴.(3)y=cos(cosx)(x∈R)的值域是[cos1,1].(4)若α,β都是第一象限角,且α>β,则tanα>tanβ.其中正确命题的题号为()A.(1)(2)B.(2)(3)C.(3)(4)D.(1)(4)16.如果对一切实数x、y,不等式﹣cos2x≥asinx﹣恒成立,则实数a的取值范围是()A.(﹣∞,]B.[3,+∞)C.[﹣2,2]D.[﹣3,3]三、解答题(共5小题,满分76分)17.(14分)如图,已知AB⊥平面BCD,BC⊥CD,AD与平面BCD 所成的角为30°,且AB=BC=2;(1)求三棱锥A﹣BCD的体积;(2)设M为BD的中点,求异面直线AD与CM所成角的大小(结果用反三角函数值表示).18.(14分)在△ABC中,a,b,c分别是角A,B,C的对边,且8sin2.(I)求角A的大小;(II)若a=,b+c=3,求b和c的值.19.(14分)某地要建造一个边长为2(单位:km)的正方形市民休闲公园OABC,将其中的区域ODC开挖成一个池塘,如图建立平面直角坐标系后,点D的坐标为(1,2),曲线OD是函数y=ax2图象的一部分,对边OA上一点M在区域OABD内作一次函数y=kx+b(k >0)的图象,与线段DB交于点N(点N不与点D重合),且线段MN与曲线OD有且只有一个公共点P,四边形MABN为绿化风景区:(1)求证:b=﹣;(2)设点P的横坐标为t,①用t表示M、N两点坐标;②将四边形MABN的面积S表示成关于t的函数S=S(t),并求S的最大值.20.(16分)已知函数f(x)=9x﹣2a•3x+3:(1)若a=1,x∈[0,1]时,求f(x)的值域;(2)当x∈[﹣1,1]时,求f(x)的最小值h(a);(3)是否存在实数m、n,同时满足下列条件:①n>m>3;②当h (a)的定义域为[m,n]时,其值域为[m2,n2],若存在,求出m、n的值,若不存在,请说明理由.21.(18分)已知无穷数列{a n}的各项都是正数,其前n项和为S n,且满足:a1=a,rS n=a n a n+1﹣1,其中a≠1,常数r∈N;(1)求证:a n+2﹣a n是一个定值;(2)若数列{a n}是一个周期数列(存在正整数T,使得对任意n∈N*,都有a n+T=a n成立,则称{a n}为周期数列,T为它的一个周期,求该数列的最小周期;(3)若数列{a n}是各项均为有理数的等差数列,c n=2•3n﹣1(n∈N*),问:数列{c n}中的所有项是否都是数列{a n}中的项?若是,请说明理由,若不是,请举出反例.参考答案与试题解析一、填空题(共12小题,1-6每题4分,7-12每题5分,共54分)1.设集合A={x||x﹣2|<1,x∈R},集合B=Z,则A∩B={2} .【考点】交集及其运算.【分析】利用交集定义求解.【解答】解:|x﹣2|<1,即﹣1<x﹣2<1,解得1<x<3,即A=(1,3),集合B=Z,则A∩B={2},故答案为:{2}【点评】本题考查交集的求法,是基础题,解题时要认真审题,注意定义法的合理运用.2.函数y=sin(ωx﹣)(ω>0)的最小正周期是π,则ω=2.【考点】正弦函数的图象.【分析】根据三角函数的周期性及其求法即可求值.【解答】解:∵y=sin(ωx﹣)(ω>0),∴T==π,∴ω=2.故答案是:2.【点评】本题主要考查了三角函数的周期性及其求法,属于基础题.3.设i为虚数单位,在复平面上,复数对应的点到原点的距离为.【考点】复数代数形式的乘除运算.【分析】利用复数的运算法则、几何意义、两点之间的距离公式即可得出.【解答】解:复数===对应的点到原点的距离==.故答案为:.【点评】本题考查了复数的运算法则、几何意义、两点之间的距离公式,考查了推理能力与计算能力,属于中档题.4.若函数f(x)=log2(x+1)+a的反函数的图象经过点(4,1),则实数a=3.【考点】反函数.【分析】由题意可得函数f(x)=log2(x+1)+a过(1,4),代入求得a的值.【解答】解:函数f(x)=log2(x+1)+a的反函数的图象经过点(4,1),即函数f(x)=log2(x+1)+a的图象经过点(1,4),∴4=log2(1+1)+a∴4=1+a,a=3.故答案为:3.【点评】本题考查了互为反函数的两个函数之间的关系与应用问题,属于基础题.5.已知(a+3b)n展开式中,各项系数的和与各项二项式系数的和之比为64,则n=6.【考点】二项式系数的性质.【分析】令二项式中的a=b=1得到展开式中的各项系数的和,根据二项式系数和公式得到各项二项式系数的和2n,据已知列出方程求出n 的值.【解答】解:令二项式中的a=b=1得到展开式中的各项系数的和4n 又各项二项式系数的和为2n据题意得,解得n=6.故答案:6【点评】求二项展开式的系数和问题一般通过赋值求出系数和;二项式系数和为2n.属于基础题.6.甲、乙两人从5门不同的选修课中各选修2门,则甲、乙所选的课程中恰有1门相同的选法有60种.【考点】排列、组合及简单计数问题.【分析】间接法:①先求所有两人各选修2门的种数,②再求两人所选两门都相同与都不同的种数,作差可得答案.【解答】解:根据题意,采用间接法:①由题意可得,所有两人各选修2门的种数C52C52=100,②两人所选两门都相同的有为C52=10种,都不同的种数为C52C32=30,故只恰好有1门相同的选法有100﹣10﹣30=60种.故答案为60.【点评】本题考查组合公式的运用,解题时注意事件之间的关系,选用间接法是解决本题的关键,属中档题.7.若圆锥的侧面展开图是半径为2cm,圆心角为270°的扇形,则这个圆锥的体积为cm3.【考点】旋转体(圆柱、圆锥、圆台).【分析】利用圆锥的侧面展开图中扇形的弧长等于圆锥底面的周长可得底面半径,进而求出圆锥的高,代入圆锥体积公式,可得答案.【解答】解:设此圆锥的底面半径为r,由题意,得:2πr=π×2,解得r=.故圆锥的高h==,∴圆锥的体积V=πr2h=cm3.故答案为:.【点评】本题考查了圆锥的计算,圆锥的侧面展开图是一个扇形,此扇形的弧长等于圆锥底面的周长,扇形的半径等于圆锥的母线长.本题就是把扇形的弧长等于圆锥底面周长作为相等关系,列方程求解.8.若数列{a n}的所有项都是正数,且++…+=n2+3n(n∈N*),则()=2.【考点】数列的求和;极限及其运算.【分析】利用数列递推关系可得a n,再利用等差数列的求和公式、极限的运算性质即可得出.【解答】解:∵ ++…+=n2+3n(n∈N*),∴n=1时,=4,解得a1=16.n≥2时,且++…+=(n﹣1)2+3(n﹣1),可得:=2n+2,∴a n=4(n+1)2.=4(n+1).∴()==2.故答案为:2.【点评】本题考查了数列递推关系、等差数列的求和公式、极限运算性质,考查了推理能力与计算能力,属于中档题.9.如图,在△ABC中,∠B=45°,D是BC边上的一点,AD=5,AC=7,DC=3,则AB的长为.【考点】余弦定理.【分析】先根据余弦定理求出∠ADC的值,即可得到∠ADB的值,最后根据正弦定理可得答案.【解答】解:在△ADC中,AD=5,AC=7,DC=3,由余弦定理得cos∠ADC==﹣,∴∠ADC=120°,∠ADB=60°在△ABD中,AD=5,∠B=45°,∠ADB=60°,由正弦定理得,∴AB=故答案为:.【点评】本题主要考查余弦定理和正弦定理的应用,在解决问题的过程中要灵活运用正弦定理和余弦定理.属基础题.10.有以下命题:①若函数f(x)既是奇函数又是偶函数,则f(x)的值域为{0};②若函数f(x)是偶函数,则f(|x|)=f(x);③若函数f(x)在其定义域内不是单调函数,则f(x)不存在反函数;④若函数f(x)存在反函数f﹣1(x),且f﹣1(x)与f(x)不完全相同,则f(x)与f﹣1(x)图象的公共点必在直线y=x上;其中真命题的序号是①②.(写出所有真命题的序号)【考点】必要条件、充分条件与充要条件的判断.【分析】①函数f(x)既是奇函数又是偶函数,则f(x)=0.②利用偶函数的定义和性质判断.③利用单调函数的定义进行判断.④利用反函数的性质进行判断.【解答】解:①若函数f(x)既是奇函数又是偶函数,则f(x)=0,为常数函数,所以f(x)的值域是{0},所以①正确.②若函数为偶函数,则f(﹣x)=f(x),所以f(|x|)=f(x)成立,所以②正确.③因为函数f(x)=在定义域上不单调,但函数f(x)存在反函数,所以③错误.④原函数图象与其反函数图象的交点关于直线y=x对称,但不一定在直线y=x上,比如函数y=﹣与其反函数y=x2﹣1(x≤0)的交点坐标有(﹣1,0),(0,1),显然交点不在直线y=x上,所以④错误.故答案为:①②.【点评】本题主要考查函数的有关性质的判定和应用,要求熟练掌握相应的函数的性质,综合性较强.11.设向量=(1,﹣2),=(a,﹣1),=(﹣b,0),其中O为坐标原点,a>0,b>0,若A、B、C三点共线,则+的最小值为8.【考点】基本不等式.【分析】A、B、C三点共线,则=λ,化简可得2a+b=1.根据+ =(+)(2a+b),利用基本不等式求得它的最小值【解答】解:向量=(1,﹣2),=(a,﹣1),=(﹣b,0),其中O为坐标原点,a>0,b>0,∴=﹣=(a﹣1,1),=﹣=(﹣b﹣1,2),∵A、B、C三点共线,∴=λ,∴,解得2a+b=1,∴+=(+)(2a+b)=2+2++≥4+2=8,当且仅当a=,b=,取等号,故+的最小值为8,故答案为:8【点评】本题主要考查两个向量共线的性质,两个向量坐标形式的运算,基本不等式的应用,属于中档题.12.如图,已知正三棱柱ABC﹣A1B1C1的底面边长为2cm,高为5cm,一质点自A点出发,沿着三棱柱的侧面绕行两周到达A1点的最短路线的长为13cm.【考点】多面体和旋转体表面上的最短距离问题.【分析】将三棱柱展开两次如图,不难发现最短距离是六个矩形对角线的连线,正好相当于绕三棱柱转两次的最短路径.【解答】解:将正三棱柱ABC﹣A1B1C1沿侧棱展开,再拼接一次,其侧面展开图如图所示,在展开图中,最短距离是六个矩形对角线的连线的长度,也即为三棱柱的侧面上所求距离的最小值.由已知求得矩形的长等于6×2=12,宽等于5,由勾股定理d==13故答案为:13.【点评】本题考查棱柱的结构特征,空间想象能力,几何体的展开与折叠,体现了转化(空间问题转化为平面问题,化曲为直)的思想方法.二、选择题(共4小题,每小题5分,满分20分)13.“x<2”是“x2<4”的()A.充分非必要条件B.必要非充分条件C.充要条件D.既非充分也非必要条件【考点】必要条件、充分条件与充要条件的判断.【分析】先求出x2<4的充要条件,结合集合的包含关系判断即可.【解答】解:由x2<4,解得:﹣2<x<2,故x<2是x2<4的必要不充分条件,故选:B.【点评】本题考察了充分必要条件,考察集合的包含关系,是一道基础题.14.若无穷等差数列{a n}的首项a1<0,公差d>0,{a n}的前n项和为S n,则以下结论中一定正确的是()A.S n单调递增B.S n单调递减C.S n有最小值D.S n有最大值【考点】等差数列的前n项和.【分析】S n=na1+d=n2+n,利用二次函数的单调性即可判断出结论.【解答】解:S n=na1+d=n2+n,∵>0,∴S n有最小值.故选:C.【点评】本题考查了等差数列的求和公式、二次函数的单调性,考查了推理能力与计算能力,属于中档题.15.给出下列命题:(1)存在实数α使.(2)直线是函数y=sinx图象的一条对称轴.(3)y=cos(cosx)(x∈R)的值域是[cos1,1].(4)若α,β都是第一象限角,且α>β,则tanα>tanβ.其中正确命题的题号为()A.(1)(2)B.(2)(3)C.(3)(4)D.(1)(4)【考点】正弦函数的定义域和值域;两角和与差的正弦函数;正弦函数的对称性;余弦函数的定义域和值域.【分析】(1)利用辅助角公式将可判断(1);(2)根据函数y=sinx图象的对称轴方程可判断(2);(3)根据余弦函数的性质可求出y=cos(cosx)(x∈R)的最大值与最小值,从而可判断(3)的正误;(4)用特值法令α,β都是第一象限角,且α>β,可判断(4).【解答】解:(1)∵,∴(1)错误;(2)∵y=sinx图象的对称轴方程为,k=﹣1,,∴(2)正确;(3)根据余弦函数的性质可得y=cos(cosx)的最大值为y max=cos0=1,y min=cos(cos1),其值域是[cos1,1],(3)正确;(4)不妨令,满足α,β都是第一象限角,且α>β,但tanα<tanβ,(4)错误;故选B.【点评】本题考查正弦函数与余弦函数、正切函数的性质,着重考查学生综合运用三角函数的性质分析问题、解决问题的能力,属于中档题.16.如果对一切实数x、y,不等式﹣cos2x≥asinx﹣恒成立,则实数a的取值范围是()A.(﹣∞,]B.[3,+∞)C.[﹣2,2]D.[﹣3,3]【考点】函数恒成立问题.【分析】将不等式﹣cos2x≥asinx﹣恒成立转化为+≥asinx+1﹣sin2x恒成立,构造函数f(y)=+,利用基本不等式可求得f(y)=3,于是问题转化为asinx﹣sin2x≤2恒成立.通过对sinx>0、sinx min<0、sinx=0三类讨论,可求得对应情况下的实数a的取值范围,最后取其交集即可得到答案.【解答】解:∀实数x、y,不等式﹣cos2x≥asinx﹣恒成立⇔+≥asinx+1﹣sin2x恒成立,令f(y)=+,则asinx+1﹣sin2x≤f(y)min,当y>0时,f(y)=+≥2=3(当且仅当y=6时取“=”),f(y)=3;min当y<0时,f(y)=+≤﹣2=﹣3(当且仅当y=﹣6时取“=”),f(y)max=﹣3,f(y)min不存在;综上所述,f(y)min=3.所以,asinx+1﹣sin2x≤3,即asinx﹣sin2x≤2恒成立.①若sinx>0,a≤sinx+恒成立,令sinx=t,则0<t≤1,再令g(t)=t+(0<t≤1),则a≤g(t)min.由于g′(t)=1﹣<0,所以,g(t)=t+在区间(0,1]上单调递减,因此,g(t)min=g(1)=3,所以a≤3;②若sinx<0,则a≥sinx+恒成立,同理可得a≥﹣3;③若sinx=0,0≤2恒成立,故a∈R;综合①②③,﹣3≤a≤3.故选:D.【点评】本题考查恒成立问题,将不等式﹣cos2x≥asinx﹣恒成立转化为+≥asinx+1﹣sin2x恒成立是基础,令f(y)=+,求得f (y)min=3是关键,也是难点,考查等价转化思想、分类讨论思想的综合运用,属于难题.三、解答题(共5小题,满分76分)17.(14分)(2017•上海一模)如图,已知AB⊥平面BCD,BC⊥CD,AD与平面BCD所成的角为30°,且AB=BC=2;(1)求三棱锥A﹣BCD的体积;(2)设M为BD的中点,求异面直线AD与CM所成角的大小(结果用反三角函数值表示).【考点】棱柱、棱锥、棱台的体积;异面直线及其所成的角.【分析】(1)由AB⊥平面BCD,得CD⊥平面ABC,由此能求出三棱锥A﹣BCD的体积.(2)以C为原点,CD为x轴,CB为y轴,过C作平面BCD的垂线为z轴,建立空间直角坐标系,由此能求出异面直线AD与CM所成角的大小.【解答】解:(1)如图,因为AB⊥平面BCD,所以AB⊥CD,又BC⊥CD,所以CD⊥平面ABC,因为AB⊥平面BCD,AD与平面BCD所成的角为30°,故∠ADB=30°,由AB=BC=2,得AD=4,AC=2,∴BD==2,CD==2,则V A﹣BCD====.(2)以C为原点,CD为x轴,CB为y轴,过C作平面BCD的垂线为z轴,建立空间直角坐标系,则A(0,2,2),D(2,0,0),C(0,0,0),B(0,2,0),M(),=(2,﹣2,﹣2),=(),设异面直线AD与CM所成角为θ,则cosθ===.θ=arccos.∴异面直线AD与CM所成角的大小为arccos.【点评】本题考查了直线和平面所成角的计算,考查了利用等积法求点到面的距离,变换椎体的顶点,利用其体积相等求空间中点到面的距离是较有效的方法,此题是中档题.18.(14分)(2017•上海一模)在△ABC中,a,b,c分别是角A,B,C的对边,且8sin2.(I)求角A的大小;(II)若a=,b+c=3,求b和c的值.【考点】余弦定理;解三角形.【分析】(I)在△ABC中有B+C=π﹣A,由条件可得:4[1﹣cos(B+C)]﹣4cos2A+2=7,解方程求得cosA 的值,即可得到A的值.(II)由余弦定理及a=,b+c=3,解方程组求得b 和c的值.【解答】解:(I)在△ABC中有B+C=π﹣A,由条件可得:4[1﹣cos (B+C)]﹣4cos2A+2=7,(1分)又∵cos(B+C)=﹣cosA,∴4cos2A﹣4cosA+1=0.(4分)解得,∴.(6分)(II)由.(8分)又.(10分)由.(12分)【点评】本题主要考查余弦定理,二倍角公式及诱导公式的应用,属于中档题.19.(14分)(2017•上海一模)某地要建造一个边长为2(单位:km)的正方形市民休闲公园OABC,将其中的区域ODC开挖成一个池塘,如图建立平面直角坐标系后,点D的坐标为(1,2),曲线OD 是函数y=ax2图象的一部分,对边OA上一点M在区域OABD内作一次函数y=kx+b(k>0)的图象,与线段DB交于点N(点N不与点D 重合),且线段MN与曲线OD有且只有一个公共点P,四边形MABN 为绿化风景区:(1)求证:b=﹣;(2)设点P的横坐标为t,①用t表示M、N两点坐标;②将四边形MABN的面积S表示成关于t的函数S=S(t),并求S的最大值.【考点】函数模型的选择与应用.【分析】(1)根据函数y=ax2过点D,求出解析式y=2x2;由,消去y得△=0即可证明b=﹣;(2)写出点P的坐标(t,2t2),代入①直线MN的方程,用t表示出直线方程为y=4tx﹣2t2,令y=0,求出M的坐标;令y=2求出N的坐标;②将四边形MABN的面积S表示成关于t的函数S(t),利用基本不等式求出S的最大值.【解答】(1)证明:函数y=ax2过点D(1,2),代入计算得a=2,∴y=2x2;由,消去y得2x2﹣kx﹣b=0,由线段MN与曲线OD有且只有一个公共点P,得△=(﹣k)2﹣4×2×b=0,解得b=﹣;(2)解:设点P的横坐标为t,则P(t,2t2);①直线MN的方程为y=kx+b,即y=kx﹣过点P,∴kt﹣=2t2,解得k=4t;y=4tx﹣2t2令y=0,解得x=,∴M(,0);令y=2,解得x=+,∴N(+,2);②将四边形MABN的面积S表示成关于t的函数为S=S(t)=2×2﹣×2×[+(+)]=4﹣(t+);由t+≥2•=,当且仅当t=,即t=时“=”成立,所以S≤4﹣2;即S的最大值是4﹣.【点评】本题考查了函数模型的应用问题,也考查了阅读理解能力,是综合性题目.20.(16分)(2017•上海一模)已知函数f(x)=9x﹣2a•3x+3:(1)若a=1,x∈[0,1]时,求f(x)的值域;(2)当x∈[﹣1,1]时,求f(x)的最小值h(a);(3)是否存在实数m、n,同时满足下列条件:①n>m>3;②当h (a)的定义域为[m,n]时,其值域为[m2,n2],若存在,求出m、n的值,若不存在,请说明理由.【考点】函数的最值及其几何意义;函数的值域.【分析】(1)设t=3x,则φ(t)=t2﹣2at+3=(t﹣a)2+3﹣a2,φ(t)的对称轴为t=a,当a=1时,即可求出f(x)的值域;(2)由函数φ(t)的对称轴为t=a,分类讨论当a<时,当≤a ≤3时,当a>3时,求出最小值,则h(a)的表达式可求;(3)假设满足题意的m,n存在,函数h(a)在(3,+∞)上是减函数,求出h(a)的定义域,值域,然后列出不等式组,求解与已知矛盾,即可得到结论.【解答】解:(1)∵函数f(x)=9x﹣2a•3x+3,设t=3x,t∈[1,3],则φ(t)=t2﹣2at+3=(t﹣a)2+3﹣a2,对称轴为t=a.当a=1时,φ(t)=(t﹣1)2+2在[1,3]递增,∴φ(t)∈[φ(1),φ(3)],∴函数f(x)的值域是:[2,6];(Ⅱ)∵函数φ(t)的对称轴为t=a,当x∈[﹣1,1]时,t∈[,3],当a<时,y min=h(a)=φ()=﹣;当≤a≤3时,y min=h(a)=φ(a)=3﹣a2;当a>3时,y min=h(a)=φ(3)=12﹣6a.故h(a)=;(Ⅲ)假设满足题意的m,n存在,∵n>m>3,∴h(a)=12﹣6a,∴函数h(a)在(3,+∞)上是减函数.又∵h(a)的定义域为[m,n],值域为[m2,n2],则,两式相减得6(n﹣m)=(n﹣m)•(m+n),又∵n>m>3,∴m﹣n≠0,∴m+n=6,与n>m>3矛盾.∴满足题意的m,n不存在.【点评】本题主要考查二次函数的值域问题,二次函数在特定区间上的值域问题一般结合图象和单调性处理,是中档题.21.(18分)(2017•上海一模)已知无穷数列{a n}的各项都是正数,其前n项和为S n,且满足:a1=a,rS n=a n a n+1﹣1,其中a≠1,常数r ∈N;(1)求证:a n+2﹣a n是一个定值;(2)若数列{a n}是一个周期数列(存在正整数T,使得对任意n∈N*,都有a n+T=a n成立,则称{a n}为周期数列,T为它的一个周期,求该数列的最小周期;(3)若数列{a n}是各项均为有理数的等差数列,c n=2•3n﹣1(n∈N*),问:数列{c n}中的所有项是否都是数列{a n}中的项?若是,请说明理由,若不是,请举出反例.【考点】数列递推式.【分析】(1)由rS n=a n a n+1﹣1,利用迭代法得:ra n+1=a n+1(a n+2﹣a n),由此能够证明a n+2﹣a n为定值.(2)当n=1时,ra=aa2﹣1,故a2=,根据数列是隔项成等差,写出数列的前几项,再由r>0和r=0两种情况进行讨论,能够求出该数列的周期.(3)因为数列{a n}是一个有理等差数列,所以a+a=r=2(r+),化简2a2﹣ar﹣2=0,解得a是有理数,由此入手进行合理猜想,能够求出S n.【解答】(1)证明:∵rS n=a n a n+1﹣1,①∴rS n+1=a n+1a n+2﹣1,②②﹣①,得:ra n+1=a n+1(a n+2﹣a n),∵a n>0,∴a n+2﹣a n=r.(2)解:当n=1时,ra=aa2﹣1,∴a2=,根据数列是隔项成等差,写出数列的前几项:a,r+,a+r,2r+,a+2r,3r+,….当r>0时,奇数项和偶数项都是单调递增的,所以不可能是周期数列,∴r=0时,数列写出数列的前几项:a,,a,,….所以当a>0且a≠1时,该数列的周期是2,(3)解:因为数列{a n}是一个有理等差数列,a+a+r=2(r+),化简2a2﹣ar﹣2=0,a=是有理数.设=k,是一个完全平方数,则r2+16=k2,r,k均是非负整数r=0时,a=1,a n=1,S n=n.r≠0时(k﹣r)(k+r)=16=2×8=4×4可以分解成8组,其中只有,符合要求,此时a=2,a n=,S n=,∵c n=2•3n﹣1(n∈N*),a n=1时,不符合,舍去.a n=时,若2•3n﹣1=,则:3k=4×3n﹣1﹣1,n=2时,k=,不是整数,因此数列{c n}中的所有项不都是数列{a n}中的项.【点评】本题考查了数列递推关系、等差数列的定义与通项公式、数列的周期性性,考查了推理能力与计算能力,属于难题.。

上海市虹口区2019-2020学年高三第一学期数学一模考试卷

上海市虹口区2019-2020学年高三第一学期数学一模考试卷

虹口区2019学年度第一学期期终学生学习能力诊断测试高三数学 试卷 2019年12月考生注意:1.本试卷共4页,21道试题,满分150分,考试时间120分钟.2.本考试分设试卷和答题纸. 作答必须涂(选择题)或写(非选择题)在答题纸上,在试卷上作答一律不得分.一、填空题(本大题满分54分)本大题共12题,第1-6题,每空填对得4分;第7-12题,每空填对得5分. 请直接将结果填写在答题纸相应题号的空格内.1. 设全集21,1,x U R A x x -⎧⎫==>⎨⎬⎩⎭若则U A =ð_______. 2.若复数31iz i-=+(i 为虚数单位),则z =_________. 3. 设,x R +∈则21x x ++的最小值为________. 4.若sin2cos 0,2cos 1x x x= 则锐角x =_________.5. 设等差数列{}n a 的前n 项和为274,12,8,n S a a S +==若则n a =_______.6. 抛物线26x y =的焦点到直线3410x y +-=的距离为________.7. 设6270127(21)(1),x x a a x a x a x --=++++L 则5________.a =8. 设1()f x -为函数2()log (41)x f x =-的反函数,则当1()2()f x f x -=时,x 的值为_______. 9. 已知,m n α是平面外的两条不同直线. 给出三个论断:①;m n ⊥②//;n α③.m α⊥以其中两个论断作为条件,余下的一个论断作为结论,写出一个正确的命题(论断用序号表示):________________.10. 的直角三角板拼在一起,则OD AB ⋅=u u u r u u u r _________.(第16题图)B11.如图,12,F F 分别是双曲线222:1x C y a-=的左、右焦点,过2F 的直线与双曲线C 的两条渐近线分别交于,A B 两点,若212,0,F A AB FB F B =⋅=u u u r u u u r u u u r u u u r则双曲线C 的焦距12F F 为________. 12. 已知函数()f x 的定义域为(],0,2,()(2),R x f x x x ∈=-当时且对任意的,x R ∈均有 (2)2().f x f x += 若不等式15()2f x ≤在(],x a ∈-∞上恒成立,则实数a 的最大值为________.二、选择题(本大题共4题,满分20分)每题有且只有一个正确答案,考生应在答题纸的相应题号上,将所选答案的代号涂黑,选对得 5分,否则一律零分.13.设,x R ∈则“11x -<”是“24x <”的 ( ) (A )充分不必要条件 (B )必要不充分条件 (C )充要条件(D )既不充分也不必要条件14.已知函数())cos(2)f x x x θθ=+++为偶函数,且在0,2π⎡⎤⎢⎥⎣⎦上为增函数,则θ的一个值可以是 ( )(A )6π (B )3π (C )23π (D )23π- 15.已知函数()2,(),f x x g x x t =+=+定义函数(),()g(),()g(),()g().f x f x x F x x f x x ≤⎧=⎨>⎩当当若对任意的,x R ∈都有()(2)F x F x =-成立,则t 的取值为 ( )(A )4- (B )2- (C )0 (D )216.正四面体ABCD 的体积为1,O 为其中心, 正四面体EFGH 与正四面体ABCD 关于点O 对称, 则这两个正四面体的公共部分的体积为 ( ) (A )13(B )12(C )23 (D )341(第18题图)三、解答题(本大题共5题,满分76分)解答下列各题必须在答题纸的规定区域内写出必要的步骤.17.(本题满分14分) 本题共2小题,每小题7分. 在ABC ∆中,18,6,cos .3a b A ===- 求 (1)角B ; (2)BC 边上的高.18.(本题满分14分) 本题共3小题,第1小题4分,第2小题5分,第3小题5分. 如图,在圆柱1OO 中,它的轴截面11ABB A 是一个边长为2的正方形,点C 为棱1BB 的中点,点111C A B 为弧的中点. 求(1)异面直线11OC AC 与所成角的大小; (2)直线1CC 与圆柱1OO 底面所成角的大小; (3)三棱锥11C OAC -的体积.19.(本题满分14分)本题共2小题,第1小题6分,第2小题8分.某企业接到生产3000台某产品的甲、乙、丙3种部件的订单,每台产品需要这3种部件的数量分别为2,2,1(单位:件).已知每个工人每天可生产甲部件6件,或乙部件3件,或丙部件2件.该企业计划安排200名工人分成三组分别生产这3种部件,生产乙部件的人数与生产甲部件的人数成正比例,比例系数为k (k 2≥为正整数).(1)设生产甲部件的人数为x ,分别写出完成甲、乙、丙3种部件生产需要的时间; (2)假设这3种部件的生产同时开工,试确定正整数k 的值,使完成订单任务的时间最短,并给出时间最短时具体的人数分组方案.20.(本题满分16分)本题共3小题,第1小题5分,第2小题5分,第3小题6分. 已知两点12(0),0),F F 设圆O :224x y +=与x 轴交于,A B 两点,且动点P 满足:以线段2F P 为直径的圆与圆O 相内切,如图所示.记动点P 的轨迹为Γ,过点2F 与x 轴不重合 的直线l 与轨迹Γ交于,M N 两点.(1) 求轨迹Γ的方程;(2) 设线段MN 的中点为Q ,直线OQ 与直线x =,R 求证:2F R l ⊥u u u u r ; (3)记,ABM ABN ∆∆的面积分别为12,,S S 求12S S -的最大值及此时直线l 的方程.21.(本题满分18分) 本题共3小题,第1小题4分,第2小题6分,第3小题8分.在数列{}n a 中,1212210,,,,2m m m a m N a a a m *-+=∈且对任意的构成以为公差的等差数列.(1)求证:456,,a a a 成等比数列; (2)求数列{}n a 的通项公式;(3)设2222323,2n n nn S S n a a a =+++-L 试问是否存在极限?若存在,求出其值;若不存在,请说明理由.A虹口区2019学年度第一学期期终学生学习能力诊断测试高三数学 参考答案和评分标准 2019年12月一、填空题(本大题满分54分)本大题共12题,第1-6题,每题填对得4分;第7-12题,每题填对得5分.1.[]0,1 21 4.4π 5.23()n n N *-∈ 6.17. 36 8. 1 9.若①③,则② (或:若②③,则①) 10.1- 11 12.274二、选择题(本大题共 4题,每题5分,满分20分)13. A 14. D 15.A 16. B 三、解答题(本大题共5题,满分76分)17.(本题满分14分)本题共2小题,每小题7分. 解:(1)在ABC ∆中,由1cos ,sin 3A A =-=得…… 2分 由正弦定理,得6sin 3sin 8b AB a=== …… 5分 于是由角A 为钝角,知.4B π=…… 7分sinC sin()cosA)2A B =+=+=() 因…… 10分设ABC ∆的BC 边上的高为h,则由11sin ,22ABC S ah ab C ∆==得sin 64h b C === 即ABC ∆的BC 边上的高等于4 …… 14分 18.(本题满分14分) 本题共3小题,第1小题4分,第2小题5分,第3小题5分.解:(1)以点O 为原点,直线1,OB OO 分别为,y z轴,建立空间直角坐标系,如图所示.则相关点的坐标为(0,0,0),(0,1,0),O B 1(0,1,2),B(0,1,1),C 111(0,1,2),(0,0,2),(1,0,2).A O C - 于是11(0,1,1),(1,1,0).OC AC ==u u u r u u u u r ……2分从而1111111cos ,,2OC A C OC A C OC A C ⋅<>===⋅u u u r u u u u ru u u r u u u u r u u u r u u u u r 因此,异面直线11OC AC 与所成角的大小为.3π……4分 (2)由于1(0,0,2)OO =u u u u r是圆柱1OO 底面的一个法向量,又1(1,1,1)CC =-u u u u r,……6分 设直线1CC 与圆柱1OO 底面所成角的大小为,θ 则111111sin cos ,=CC OO CC OO CC OO θ⋅=<>==⋅u u u u r u u u u ru u u u r u u u u r u u u u r u u u u r于是,直线1CC 与圆柱1OO底面所成角的大小为 …… 9分 (3)由于三棱锥11C OAC -的顶点11111,C OA C C O =到面的距离为 …… 11分 而 111111111322121121.2222OA C OAA OBC A B C ABB A S S S S S ∆∆∆∆=---=⨯-⨯⨯-⨯⨯-⨯⨯=正方形故 1111111311.3322C OA C OA C V S O C -∆=⋅=⨯⨯= …… 14分 19.(本题满分14分) 本题共2小题,第1小题6分,第2小题8分.解:(1)设完成甲、乙、丙3种部件生产需要的时间(单位:天)分别为123(),(),(),T x T x T x 则由题意,得[]12323000100023000200030001500(),(),(),63()2200(1)200(1)T x T x T x x x k x kx k x k x⨯⨯======-+-+即123100020001500(),(),(),200(1)T x T x T x x kx k x===-+ ……4分 其中,,200(1)x kx k x -+均为1到200的正整数,且.k N *∈ ……6分(2)完成订单所用的时间为{}123()max (),(),(),f x T x T x T x =其定义域为2001,,,2.1x x x k N k k *⎧⎫≤<∈≥⎨⎬+⎩⎭且 由于1210002000(),()T x T x x kx ==均为减函数,31500()200(1)T x k x=-+为增函数,并注意到212()().T x T x k=……8分 (i )当2k =时,12()(),T x T x =此时{}12310001500()max (),(),()max ,,2003f x T x T x T x x x ⎧⎫==⎨⎬-⎩⎭其中{}166,.x x x N *≤≤∈且由13(),()T x T x 的单调性知,当100015002003x x =-时,()f x 取得最小值,解得400.9x =由于134002503004445,(44)T (44),(45)T (45),(44)(45).91113f f f f <<====<而故 当44x =时,完成订单任务所用的时间最短,最短时间为25011天. ……11分(ii )当2k >时,12()(),T x T x > 由于,3,k N k *∈≥故此时3375()(),()50T x T x T x x≥=-且为增函数.于是 {}{}1311000375()max (),()max (),() = g()max ,.50f x T x T x T x T x x x x ⎧⎫=≥=⎨⎬-⎩⎭由1(),()T x T x 的单调性知,当100037550x x=-时,()g x 取得最小值,解得400.11x =由于134002502503752503637,(36)T (36),(37)T (37),119111311g g <<==>==>而此时完成订单任务的最短时间大于25011天.综上所述,当2k =时,完成订单任务所用时间最短,最短时间为25011天;此时生产甲、乙、丙3种部件的人数分别为44,88,68人. ……14分20.(本题满分16分)本题共3小题,第1小题5分,第2小题5分,第3小题6分. 解:(1)连结1,PF 设2PF 的中点为,C 则12.PF CO = 由圆C 与圆O 相内切,得 22,CO CF +=于是 1222()4,PF PF CO CF +=+= ……3分 因此,动点P 的轨迹是:以12,F F 为焦点,4为长轴长的椭圆;其方程为 22 1.4x y +=……5分证:(2)设直线l的方程为x my =并设1122(,),(,),M x yN x y 则由2244,x my x y ⎧=⎪⎨+=⎪⎩ 22(m 4)10,y ++-=得 故121221.4y y y y m +==-+从而1212()x x m y y+=++=于是Q……7分所以),OQ m=-u u u r于是直线40.OQ mx y+=的方程为由40,mx yx+=⎧⎪⎨=⎪⎩解得),R从而2)).F R m==-u u u u r由于直线l的法向量2(1,m)//,F R-u u u u r故2.F R l⊥u u u u r……10分解:(3)由(2)知121221.4y y y ym+==-+故111222112,2,22S AB y y S AB y y=⋅==⋅=……12分而120,y y<故12121222S S y y y y-=+=-=……14分由于12S S-最大时0,m≠故12mmS S-=≤=+当且仅当2m=时,等号成立.因此12maxS S-=此时直线l的方程为20,20.x y x y+=-或……16分21. (本题满分18分)本题共3小题,第1小题4分,第2小题6分,第3小题8分.证:(1)因为1212210,,,,2m m ma m N a a a m*-+=∈且对任意的构成以为公差的等差数列.所以,当121321,0,22,24;m a a a a a===+==+=时当343542,4,48,412;m a a a a a===+==+=时……2分当565763,12,618,624.m a a a a a===+==+=时于是65543,2a aa a==故456,,a a a成等比数列. ……4分解:(2)由题意,对2121,4,m mm N a a m*+-∈-=任意的有于是2121212123311()()()(1)44(1)41042(1),2m m m m m a a a a a a a a m m m m m m ++---=-+-++-++=+-++⨯+=⋅=+L L结合10,a =得212(1)().m a m m m N +=+∈令121,,2n m n m -+==则得21112().222n n n n a n -+-=⋅⋅=为奇数 ……7分由题意,对2221,22(1)22,m m m N a a m m m m m *+∈=-=+-=任意的有 故对正偶数,n 有 222().22n n n a ==因此,数列{}n a 的通项公式为2221,(1)12().24,2n n n n n n a a n N n n *⎧-⎪--⎪==+∈⎨⎪⎪⎩为奇数,或为偶数,……10分 解:(3)对于任意的,k N *∈有22222221(2)4(21)44111112,22().22(1)2(1)21k k k k k k k a k a k k k k k k ++++====+=+-+++ ……12分下面分n 为偶数与奇数两种情况讨论:(i )当n 为偶数时,设2(),n k k N *=∈22222,S a ==则当2k ≥时,222222242352124(2)35(21)111111()()22(1)(1)()()22231113142(1)2.22n k k k k S k k a a a a a a k k k n k n--⎡⎤=+++++++=+-+-+-++-⎢⎥-⎣⎦=-+-=--L L L 于是312.2nS n n-=-- ……15分(ii )当n 为奇数时,设21(),n k k N *=+∈则当2k ≥时,222222242352124(2)35(21)111111()()22(1)()()2223111314(1)2.2121n k k k k S k k a a a a a a k k k n k n ++⎡⎤=+++++++=++-+-++-⎢⎥+⎣⎦=+-=--++L L L 于是312.21nS n n -=--+综上,得31,3,21231.2n n n S n n n ⎧--≥⎪⎪+-=⎨⎪--⎪⎩为奇数,为正偶数于是2n S n -存在极限,且3lim (2).2nn S n →+∞-=-……18分。

2019年上海市高三数学一模分类汇编:立体几何

2019年上海市高三数学一模分类汇编:立体几何

2(2019杨浦一模). 已知扇形的半径为6,圆心角为3π,则扇形的面积为 5(2019普陀一模). 若一个球的体积是其半径的43倍,则该球的表面积为 5(2019长嘉一模). 若圆锥的侧面面积为2π,底面面积为π,则该圆锥的体积为 5(2019虹口一模). 若一个球的表面积为4π,则它的体积为5(2019青浦一模). 已知直角三角形△ABC 中,90A ∠=︒,3AB =,4AC =,则△ABC 绕直线AC 旋转一周所得几何体的体积为6(2019杨浦一模). 若圆锥的母线长5()l cm =,高4()h cm =,则这个圆锥的体积等于 3()cm8(2019浦东一模). ,母线与底面所成角为3π,则该圆锥的表面积为8(2019崇明一模). 设一个圆锥的侧面展开图是半径为2的半圆,则此圆锥的体积等于 9(2019普陀一模). 如图,正四棱柱1111ABCD A B C D -的底面边长为4,记1111AC B D F =I ,11BC B C E =I ,若AE BF ⊥,则此棱柱的体积为9(2019闵行一模). 如图,在过正方体1111ABCD A B C D -的任意两个顶点的所有直线中,与直线1AC 异面的直线的条数为10(2019金山一模). 在120︒的二面角内放置一个半径为6的小球,它与二面角的两个半平面相切于A 、B 两点,则这两个点在球面上的距离是10(2019静安一模). 已知球的半径为24cm ,一个圆锥的高等于这个球的直径,而且球的表面积等于圆锥的表面积,则这个圆锥的体积是 3cm (结果保留圆周率π)10(2019宝山一模). 将函数y =y 轴旋转一周所得的几何容器的容积是14(2019徐汇一模). 魏晋时期数学家刘徽在他的著作《九章算术注》中,称一个正方体内两个互相垂直的内切圆柱所围成的几何体为“牟合方盖”,刘徽通过计算得知正方体的内切球的体积与“牟合方盖”的体积之比应为:4π,若正方体的棱长为2,则“牟合方盖”的体积为( )A. 16B. 163C. 163D. 128314(2019金山一模). 给定空间中的直线l 及平面α,条件“直线l 与平面α内无数条直线都垂直”是“直线l 与平面α垂直”的( )A. 充分非必要条件B. 必要非充分条件C. 充要条件D. 既非充分也非必要条件14(2019虹口一模). 关于三个不同平面α、β、γ与直线l ,下来命题中的假命题是( ) A. 若αβ⊥,则α内一定存在直线平行于βB. 若α与β不垂直,则α内一定不存在直线垂直于βC. 若αγ⊥,βγ⊥,l αβ=I ,则l γ⊥D. 若αβ⊥,则α内所有直线垂直于β14(2019奉贤一模). 若空间中有四个点,则“这四个点中有三点在同一直线上”是“这四个点在同一平面上”的( )A. 充分非必要条件B. 必要非充分条件C. 充要条件D. 非充分非必要条件14(2019闵行一模). 已知a 、b 为两条不同的直线,α、β为两个不同的平面,a αβ=I ,a ∥b ,则下列结论不可能成立的是( )A. b β,且b ∥αB. b α,且b ∥βC. b ∥α,且b ∥βD. b 与α、β都相交14(2019浦东一模). 下列命题正确的是( )A. 如果两条直线垂直于同一条直线,那么这两条直线平行B. 如果两条直线垂直于同一条直线,那么这两条直线平行C. 如果两条直线垂直于同一条直线,那么这两条直线平行D. 如果两条直线垂直于同一条直线,那么这两条直线平行15(2019黄浦一模). 如图,在正方体1111ABCD A B C D -的八个顶点中任取两个点作直线,与直线1A B 异面且夹角成60︒的直线的条数为( )A. 3B. 4C. 5D. 615(2019青浦一模). 对于两条不同的直线m 、n 和两个不同的平面α、β,以下结论正确的是( )A. 若m α,n ∥β,m 、n 是异面直线,则α、β相交B. 若m α⊥,m β⊥,n ∥α,则n ∥βC. mα,n ∥α,m 、n 共面于β,则m ∥n D. 若m α⊥,n β⊥,α、β不平行,则m 、n 为异面直线15(2019普陀一模). 若a 、b 、c 表示直线,α、β表示平面,则“a ∥b ”成立的一个充分非必要条件是( )A. a b ⊥,b c ⊥B. a ∥α,b ∥αC. a β⊥,b β⊥D. a ∥c ,b c ⊥17(2019浦东一模). 已知直三棱柱111A B C ABC -中,11AB AC AA ===,90BAC ︒∠=.(1)求异面直线1A B 与11B C 所成角;(2)求点1B 到平面1A BC 的距离.17(2019金山一模). 如图,三棱锥P ABC -中,PA ⊥底面ABC ,M 是 BC 的中点,若底面ABC 是边长为2的正三角形,且PB 与底面ABC 所成的角为3π. 求: (1)三棱锥P ABC -的体积;(2)异面直线PM 与AC 所成角的大小.(结果用反三角函数值表示)17(2019黄浦一模). 如图,一个圆锥形量杯的高为12厘米,其母线与轴的夹角为30︒.(1)求该量杯的侧面积S ;(2)若要在该圆锥形量杯的一条母线PA 上,刻上刻度,表示液面到达这个刻度时,量杯里的液体的体积是多少,当液体体积是100立方厘米时,刻度的位置B 与顶点P 之间的距离是多少厘米(精确到0.1厘米)?17(2019奉贤一模). 如图,三棱柱111ABC A B C -中,1AA ⊥底面ABC ,AB AC =,D 是BC 的中点.(1)求证:BC ⊥平面11A AD ;(2)若90BAC ︒∠=,4BC =,三棱柱111ABC A B C -的 体积是83,求异面直线1A D 与1AB 所成角的大小.17(2019青浦一模). 已知正四棱柱1111ABCD A B C D -的底面边长为3,15A D =.(1)求该正四棱柱的侧面积与体积;(2)若E 为线段1A D 的中点,求BE 与平面ABCD 所成角的大小.17(2019闵行一模). 如图,正三棱柱111ABC A B C -的各棱长均为2,D 为棱BC 的中点.(1)求该三棱柱的表面积;(2)求异面直线AB 与1C D 所成角的大小.17(2019宝山一模). 如图,在四棱锥P ABCD -中,PA ⊥平面ABCD ,正方形ABCD 的边长为2,4PA =,设E 为侧棱PC 的中点.(1)求正四棱锥E ABCD -的体积V ;(2)求直线BE 与平面PCD 所成角θ的大小.17(2019崇明一模). 如图,设长方体1111ABCD A B C D -中,2AB BC ==,直线1A C 与平面ABCD 所成的角为4π. (1)求三棱锥1A A BD -的体积;(2)求异面直线1A B 与1B C 所成角的大小.17(2019徐汇一模). 如图,已知正方体ABCD A B C D ''''-的棱长为1.(1)正方体ABCD A B C D ''''-中哪些棱所在的直线与直线A B '是异面直线?(2)若M 、N 分别是A B '、BC '的中点,求异面直线MN 与BC 所成角的大小.17(2019虹口一模). 在如图所示的圆锥中,底面直径与母线长均为4,点C 是底面直径AB 所对弧的中点,点D 是母线PA 的中点.(1)求该圆锥的侧面积与体积;(2)求异面直线AB 与CD 所成角的大小.17(2019杨浦一模). 如图,PA ⊥平面ABCD ,四边形ABCD 为矩形,1PA AB ==,2AD =,点F 是PB 的中心,点E 在边BC 上移动.(1)求三棱锥E PAD -的体积;(2)证明:无论点E 在边BC 的何处,都有AF ⊥PE .18(2019静安一模). 如图,在四棱锥P ABCD -中,底面ABCD 是菱形,PA ⊥平面ABCD ,PA AC AB ==,E 、F 分别是CD 、PD 的中点.(1)求证:CD ⊥平面PAE ;(2)求异面直线AF 与PE 所成角的大小.(结果用反三角函数值表示)18(2019长嘉一模). 《九章算术》中,将底面为长方形且有一条侧棱与地面垂直的四棱锥称之为阳马,将四个面都为直角三角形的四面体称之为鳖臑,首届中国国际进口博览会的某展馆棚顶一角的钢结构可以抽象为空间图形阳马,如图所示,在阳马P ABCD -中,PD ⊥底面ABCD .(1)已知4AD CD m ==,斜梁PB 与底面ABCD 所成角为15︒,求立柱PD 的长; (精确到0.01m )(2)求证:四面体PDBC 为鳖臑.19(2019普陀一模). 如图所示,某地出土的一种“钉”是由四条线段组成,其结构能使它任意抛至水平面后,总有一端所在的直线竖直向上,并记组成该“钉”的四条线段的公共点为O ,钉尖为i A (1,2,3,4i =).(1)记i OA a =(0a >),当1A 、2A 、3A 在同一水平面内时,求1OA 与平面123A A A 所成角的大小(结果用反三角函数值表示);(2)若该“钉”的三个钉尖所确定的三角形的面积为232cm ,要用某种线型材料复制100枚这种“钉”(耗损忽略不计),共需要该种材料多少米?。

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(第11题图)虹口区2018学年度第一学期教学质量监控测试1.计算153lim ________.54n nnnn +→+∞-=+ 2. 不等式21xx >-的解集为_________. 3.设全集{}{}3,2,1,0,1,2log (1),U R A B x y x ==--==-若,则()U A B =I ð_______. 4. 设常数,a R ∈若函数()()3log f x x a =+的反函数的图像经过点()2,1,则a =_______. 5. 若一个球的表面积为4,π 则它的体积为________. 6. 函数8()f x x x=+[)(2,8)x ∈的值域为________. 7.二项式62x ⎫⎪⎭的展开式的常数项为________.8. 双曲线22143x y -=的焦点到其渐近线的距离为_________.9. 若复数z =sin 1cos i iθθ-(i 为虚数单位),则z 的模的最大值为_________. 10.已知7个实数1,2,4,,,,a b c d -依次构成等比数列,若从这7个数中任取2个,则它们的和为正数的概率为__________.11.如图,已知半圆O 的直径4,AB = OAC ∆是 等边三角形,若点P 是边AC (包含端点,A C )上的动点,点Q 在弧»BC 上,且满足,OQ OP ⊥ 则OP BQ ⋅uur uu u r的最小值为__________.12.若直线y k x =与曲线2log (2)21x y x +=--恰有两个公共点,则实数k 的取值范围为________.二、选择题(本大题共4题,满分20分)每题有且只有一个正确答案,考生应在答题纸的相应题号上,将所选答案的代号涂黑,选对得 5分,否则一律零分. 13.已知,x R ∈则“1233x -<”是“1x <”的 ( )(A )充分非必要条件 (B )必要非充分条件 (C )充要条件 (D )既非充分又非必要条件14.关于三个不同平面,,αβγ与直线l ,下列命题中的假命题是 ( )(第17题图)B(A )若,αβ⊥则α内一定存在直线平行于β(B )若αβ与不垂直,则α内一定不存在直线垂直于β (C )若,,l αγβγαβ⊥⊥⋂=, 则l γ⊥ (D )若,αβ⊥则α内所有直线垂直于β15.已知函数21,1,()1,(),11,1,1,x f x a x x g x x x x -≤-⎧⎪=-+=-<<⎨⎪≥⎩若函数()()y f x g x =-恰有两个零点,则实数a 的取值范围为 ( )(A )(0,)+∞ (B )(,0)(0,1)-∞⋃ (C )1(,)(1,)2-∞-⋃+∞ (D )(,0)(0,2)-∞⋃16.已知点E 是抛物线2:2(0)C y p x p =>的对称轴与准线的交点,点F 为抛物线C 的 焦点,点P 在抛物线C 上.在EFP ∆中,若sin sin EFP FEP μ∠=⋅∠,则μ的最大值为()(A(B(C(D 三、解答题(本大题共5题,满分76分)解答下列各题必须在答题纸的规定区域内写出必要的步骤.17.(本题满分14分) 本题共2小题,第1小题6分,第2小题8分. 在如图所示的圆锥中,底面直径与母线长均为4, 点C 是底面直径AB 所对弧的中点,点D 是母线PA 的中点.(1)求该圆锥的侧面积与体积;(2)求异面直线AB 与CD 所成角的大小.18.(本题满分14分)本题共2小题,第1小题6分,第2小题8分.已知函数16()1(0,1)x f x a a a a+=->≠+是定义在R 上的奇函数.(1)求实数a 的值及函数()f x 的值域;(2)若不等式 ()[]331,2x t f x x ⋅≥-∈在上恒成立,求实数t 的取值范围.19.(本题满分14分) 本题共2小题,每小题7分.(第19题图)某城市的棚户区改造建筑用地平面示意图如图所示,经过调研、规划确定,棚改规划用地区域近似为圆面,该圆的内接四边形ABCD 区域是原棚户区建筑用地,测量可知边界2()3(),1().AB AD k m BC k m CD k m ====,(1) 求AC 的长及原棚户区建筑用地ABCD 的面积; (2)因地理条件限制,边界,AD DC 不能变更,而 边界,AB BC 可以调整,为了增加棚户区建筑用地的面积,请在弧 ¼ABC 上设计一点,P 使得棚户区改造后的 新建筑用地(四边形APCD )的面积最大,并求出这 个面积最大值.20.(本题满分16分)本题共3小题,第1小题5分,第2小题5分,第3小题6分. 设椭圆22:1,2x y Γ+=点F 为其右焦点, 过点F 的直线与椭圆Γ相交于点,.P Q (1) 当点P 在椭圆Γ上运动时,求线段FP 的中点M 的轨迹方程;(2) 如图1,点R 的坐标为(2,0),若点S 是点P 关于x 轴的对称点,求证:点,,Q S R 共线;(3) 如图2,点T 是直线:2l x =上的任意一点,设直线,,PT FT QT 的斜率分别为,PT k,,FT QT k k 求证:,,PT FT QT k k k 成等差数列;(第20题图1)(第20题图2)21.(本题满分18分) 本题共3小题,第1小题4分,第2小题6分,第3小题8分.对于()n n N *∈个实数构成的集合{}12,,,n E e e e =L ,记12E n S e e e =+++L .已知由n 个正整数构成的集合{}12,,,n A a a a =L 12(,3)n a a a n <<<≥L 满足:对于任意不大于A S 的正整数,m 均存在集合A 的一个子集,使得该子集的所有元素之和等于.m (1)试求12,a a 的值;(第17题图)(2)求证:“12,,,n a a a L 成等差数列”的充要条件是“1(1)2A S n n =+”;(3)若2018A S =, 求证:n 的最小值为11;并求n 取最小值时,n a 的最大值.虹口区2018学年度第一学期期终教学质量监控测试高三数学 参考答案和评分标准 2018年12月一、填空题(本大题满分54分)本大题共12题,第1-6题,每空填对得4分;第7-12题,每空填对得5分. 请直接将结果填写在答题纸相应题号的空格内. 1.5 2.()1,2 3.{}1,2 4.8 5.43π6. )9⎡⎣ 7. 60 8 10.4711.2 12.(]{},01-∞⋃二、选择题(本大题共4题,每题5分,满分20分)13. A 14. D 15. B 16. C 三、解答题(本大题共5题,满分76分)17.(本题满分14分) 本题共2个小题,第1小题6分,第2小题8分.解:(1)由已知,得圆锥的底面半径为2OA =,高为OP = …… 2分 故该圆锥的侧面积为248S OA PA πππ=⋅⋅=⨯⨯=. …… 4分该圆锥的体积21()3V OA OP π=⋅⋅⋅=. …… 6分 (2)以直线,,OC OB OP 分别为,,x y z 轴,建立空间直角坐标系,则相关点的坐标为(0,2,0)A -,(0,2,0),B(2,0,0),(0,0,(0,C P D -于是(0,4,0),(2,AB CD ==--u u u r u u u r (10)分故 cos ,4AB CD AB CD AB CD⋅<>===-⋅u u u r u u u ru u u r u u u r u uu r u u u r 因此异面直线AB 与CD 所成角的大小为…… 14分 18.(本题满分14分)本题共2小题,第1小题6分,第2小题8分. 解:(1)由()f x 是R 上的奇函数,知(0)0,f =610, 3.a a a-==+解得(第19题图)此时31(),31x x f x -=+故对于任意的3131,()()0,3131x x x x x R f x f x ----∈+-=+=++有即()f x 是R 上的奇函数;因此实数a 的值为3. …… 4分令31(),31x x f x y -==+则130,1x yy+=>-解得11,y -<<即函数()f x 的值域为()1,1.-…6分(2)解法1:由(1)知31(),31x x f x -=+于是不等式 ()33xt f x ⋅≥-可化为2(3)(2)3(3)0.x xt t -+⋅+-≤ …… 8分 令[][]33,9(1,2)x u x =∈∈因,则不等式2(2)(3)0u t u t -+⋅+-≤在[]3,9u ∈上恒成立.设2()(2)(3),g u u t u t =-+⋅+- 则()0g u ≤在[]3,9u ∈上恒成立, …… 10分等价于(3)0.(9)0g g ≤⎧⎨≤⎩即0(3)93(2)(3)015.15(9)819(2)(3)022t g t t t g t t t ≥⎧=-++-≤⎧⎪⇔⇔≥⎨⎨=-++-≤≥⎩⎪⎩因此,实数t 的取值范围为15,.2⎡⎫+∞⎪⎢⎣⎭…… 14分 (2)解法2:由(1)知31(),31x x f x -=+当[]1,2x ∈时,()0.f x >于是不等式()33x t f x ⋅≥-可化为()233(33)(31)(31)44(31).313131x x xx xx x xt f x --+--≥===----- …… 10分令[][]312,8(1,2)x v x -=∈∈因,则由函数[]4()2,8v v vϕ=-在上递增知,max 15()(8).2v ϕϕ==故由max ()t v ϕ≥恒成立知,实数t 的取值范围为15,.2⎡⎫+∞⎪⎢⎣⎭…… 14分19.(本题满分14分) 本题共2小题,每小题7分.解:(1)设,AC x =则由余弦定理,得2222222321cos ,cos .223221x x B D +-+-==⋅⋅⋅⋅由四边形ABCD 是圆内接四边形,得180,B D ∠+∠=︒ 故cos cos 0,B D +=从而2222222232107,223221x x x AC +-+-+=⇔==⋅⋅⋅⋅即……3分从而1cos =60=120.2B B D =⇒∠︒∠︒, ……5分故 11=+23sin 6021sin12022ABC ADC ABCD S S S ∆∆=⋅⋅⋅︒+⋅⋅⋅︒=四边形答:AC (km ),原棚户区建筑用地ABCD 的面积为2)k m . ……7分(2)解法1:由条件及“同弧所对的圆周角相等”得60P B ∠=∠=︒.要使棚户区改造后的新建筑用地APCD 的面积更大,必须使APC ∆的面积最大,即点P 到AC 的距离最大,从而点P 在弦AC 的垂直平分线上,即.PA PC = ……10分于是APC ∆为等边三角形,2()AC = (12)分因此,棚户区改造后的新建筑用地APCD ADC S ∆==即当APC ∆为等边三角形时,新建筑用地APCD 2).k m ……14分(2)解法2:由条件及“同弧所对的圆周角相等”得60P B ∠=∠=︒.设1,(,0),sin .2APC PA u PC v u v S uv P ∆==>=⋅∠=则 ……9分在APC ∆中,由余弦定理,有222227=2cos (),4APC AC u v uv P u v uv uv ∆=+-⋅∠=+-≥==故APC S ∆≤当且仅当u v ==. (12)分因此,棚户区改造后的新建筑用地APCD面积的最大值为4424ADC S ∆+=+= 即当APC ∆为等边三角形时,新建筑用地APCD2).k m ……14分 20.(本题满分16分)本题共3小题,第1小题5分,第2小题5分,第3小题6分.(第20题图1)(第20题图2)解:(1)易知(1,0),F 设11(,),(,),M x y P x y 则由M 为线段FP 的中点,得11111212.022x x x x y y y y +⎧=⎪=-⎧⎪⇒⎨⎨+=⎩⎪=⎪⎩ ……2分 于是,由点11(,)P x y 在椭圆22:12x y Γ+=上,得 22(21)(2)12x y -+=,即点M 的轨迹方程为 22(21)82x y -+=. ……5分证:(2)当过点F 的直线与x 轴重合时,点P 与S 重合,点,Q S 分别为椭圆在x 轴的两个顶点,显然点,,Q S R 共线.当过点F 的直线与x 轴不重合时,设其方程为11221,(,),(,),x m y P x y Q x y =+且则11(,),S x y -由221,1,2x m y x y =+⎧⎪⎨+=⎪⎩得22(2)210m y my ++-=,显然0.∆> 所以 12122221,,22my y y y m m +=-=-++ 于是 22221111(2,)(1,),(2,)(1,),RQ x y my y RS x y my y =-=-=--=--u u u r u u u r故 22112211,,2121RQ RS y y y y k k x my x my --====---- (8)分所以21121221122()0,11(1)(1)RQ RS y y my y y y k k my my my my -+-=+==----即RQ RS k k =,因此点,,Q S R 共线. ……10分证:(3)由T 是直线:2l x =上的点,可设其坐标为(2,).t当过点F 的直线与x轴重合时,有(P Q 从而+2,,21PT QT FT tk k t k t ====-故 2.PT QT FS k k k += (12)分当过点F 的直线与x 轴不重合时,其方程为11221,(,),(,),x m y P x y Q x y =+且有11221122,,,212121PT QT FT y t y t y t y t tk k k t x my x my ----======----- 由(2)知12122221,,22my y y y m m +=-=-++ 于是 121221121221212121222222222()(1)()(1)2(1)()211(1)(1)()122(1)24(1)222222(1)122PT QT FTy t y t y t my y t my my y t m y y tk k my my my my m y y m y y m m t m tt m m m t k m m m m m ----+---++++=+==-----+++-+++++====+-++++即2,PT QT FS k k k +=综合上述,得,,PT FT QT k k k 成等差数列. ……16分21. (本题满分18分) 本题共3小题,第1小题4分,第2小题6分,第3小题8分. 解:(1)由条件,知A 1S ,1.A ≤∈必有又12n a a a <<<L 均为正整数,故1=1.a ……2分由条件,知A 2S ,≤故由A S 的定义及12n a a a <<<L 均为正整数,2,A ∈必有于是2=2.a……4分 证:(2)必要性 由“123,,,,n a a a a L 成等差数列”及12=1,=2a a 得=(1,2,,).i a i i n =L此时{}1,2,3,,1,A n n =-L ,满足题设条件;从而12112(1).2A n S a a a n n n =+++=+++=+L L ……7分 充分性 由条件知12n a a a <<<L ,且它们均为正整数,可得(1,2,,)i a i i n ≥=L ,故 112(1)2A S n n n ≥+++=+L 当且仅当(1,2,,)i a i i n ==L 时,上式等号成立. 于是当1(1)2A S n n =+时,=(1,2,,)i a i i n =L ,从而123,,,,n a a a a L 成等差数列. 因此 “123,,,,n a a a a L 成等差数列”的充要条件是“1(1)2AS n n =+”. ……10分 证:(3)由于n 元集合A 的非空子集的个数为21,n-故当10n =时,10211023,-=此时A的非空子集的元素之和最多表示出1023个不同的正整数,m 不符合要求. ……12分而用11个元素的集合{}1,2,4,8,1632641282565121024M =,,,,,,的非空子集的元素之和可以表示2047个正整数:1,232046,2047.L ,,, 因此当2018A S =时,n 的最小值为11. ……14分 当2018A S =,n 取最小值11时,设101210,S a a a =+++L 由题设得10112018,S a += 并且10111.S a +≥事实上,若10111,S a +<则101111112019201821,2S a a a =+<-⇒>由11,a N *∈故111010.a ≥此时101008,S ≤从而1009m =时,其无法用A 的非空子集的元素之和表示,与题意矛盾!于是由10112018,S a +=与10111,S a +≥可得 101111112019201821,2S a a a =+≥-⇒≤故由11,a N *∈得111009.a ≤ ……16分当11=1009a 时,用{}1,2,4,8,163264128256,498,1009A =,,,,的非空子集的元素之和可以表示出1,2,3,…,2017,2018中的每一个数.因此,当2018A S =时,n 的最小值为11,n a 的最大值为1009. ……18分。

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