安徽省安庆一中、江西省南昌二中等五省六校(K12联盟)2018届高三上学期期末联考英语试题Word版含答案
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K12联盟2018届高三年级第一学期期末检测联考数学(文科试题)第Ⅰ卷(共60分)一、选择题:本大题共12个小题,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. 若集合,,则()A. B. C. D.【答案】C【解析】由题意得,,故选C.点睛:研究一个集合,我们首先要看清楚它的研究对象,是实数还是点的坐标还是其它的一些元素,这是很关键的一步.第二步常常是不等式,求得不等式的解集.在解分式不等式的过程中,要注意分母不能为零.解指数或对数不等式要注意底数对单调性的影响.元素与集合之间是属于和不属于的关系,集合与集合间有包含关系.2. 已知复数(,)满足,则的概率为()A. B. C. D.【答案】B...........................满足的图象如图中圆内阴影部分所示:则概率故选B.3. 某中学有高中生960人,初中生480人,为了了解学生的身体状况,采用分层抽样的方法,从该校学生中抽取容量为的样本,其中高中生有24人,那么等于()A. 12B. 18C. 24D. 36【答案】D【解析】∵有高中生人,初中生人∴总人数为人∴其高中生占比为,初中生占比为故选D.4. 已知是等比数列的公比,则“数列是递增数列”是“”的()A. 充分不必要条件B. 必要不充分条件C. 充要条件D. 既不充分也不必要条件【答案】D【解析】充分性:若数列是递增数列,则,或者,,故充分性不成立;必要性:等比数列中,,若,则等比数列单调递减,故必要性不成立.综上,“数列是递增数列”是“”的既不充分也不必要条件故选D.5. 已知,,若不等式恒成立,则的最大值为()A. 9B. 12C. 18D. 24【答案】B【解析】∵,不等式恒成立∴∵当且仅当a=3b时取等号,∴的最大值为12故选:B点睛:本题主要考查基本不等式,其难点主要在于利用三角形的一边及这条边上的高表示内接正方形的边长.在用基本不等式求最值时,应具备三个条件:一正二定三相等.①一正:关系式中,各项均为正数;②二定:关系式中,含变量的各项的和或积必须有一个为定值;③三相等:含变量的各项均相等,取得最值.6. 执行如图所示的程序框图,如果输入的,则输出的()A. B. C. D.【答案】B【解析】输入,,,进入循环:,,不满足,进入循环;,,不满足,进入循环;,,不满足,进入循环;,,不满足,进入循环;,,满足,退出循环,输出.故选B.点睛:算法与流程图的考查,侧重于对流程图循环结构的考查.先明晰算法及流程图的相关概念,包括选择结构、循环结构、伪代码,其次要重视循环起点条件、循环次数、循环终止条件,更要通过循环规律,明确流程图研究的数学问题,是求和还是求项.7. 函数在上单调递增,则的取值不可能为()A. B. C. D.【答案】D【解析】∵∴令,即∵在上单调递增∴且∴故选D.8. 已知定义在上的函数,若函数为偶函数,且对任意,()都有,若,则实数的取值范围是()A. B. C. D.【答案】A【解析】∵函数为偶函数∴的图像关于对称∵对任意,()都有∴函数在上单调递增,在上单调递减∵∴∴故选A.点睛:本题主要考查抽象函数函数的奇偶性、单调性及对称性,属于难题.解决这类问题,一定要多读题,挖掘出隐含条件,其次要先从熟悉的知识点入手,有点到面逐步展开,解答本题的关键是从“是上的偶函数”得到函数关于对称,进而利用单调性解不等式可得结果.9. 双曲线:(,)的焦点为、,抛物线:的准线与交于、两点,且以为直径的圆过,则椭圆的离心率的平方为()A. B. C. D.【答案】C【解析】∵抛物线的方程为∴抛物线的焦点坐标为,准线方程为∵双曲线:(,)的焦点为、,且抛物线的准线与交于、两点∴,∵以为直径的圆过∴,即∵∴,即∴∵椭圆的离心率为∴椭圆的离心率的平方为故选C.点睛:本题主要考查利用椭圆,双曲线及抛物线的简单性质求椭圆的离心率范围,属于难题. 求解与双曲线、抛物线性质有关的问题时要结合图形进行分析,既使不画出图形,思考时也要联想到图形,当涉及顶点、焦点、实轴、虚轴、渐近线等双曲线的基本量时,要理清它们之间的关系,挖掘出它们之间的内在联系.求离心率的值或离心率范围,应先将有关的一些量表示出来,再利用其中的一些关系构造出关于的方程或不等式,从而求出.10. 已知一个几何体的正视图、侧视图、俯视图如图所示,则该几何体的体积是()A. 34B. 22C. 12D. 30【答案】B【解析】由该几何体的三视图可知,该几何体是一个三棱锥,如图所示:其中,正方体是棱长为,,,∴∴故选B.11. 在平面直角坐标系中,过点,向圆:()引两条切线,切点分别为、,则直线过定点()A. B. C. D.【答案】B【解析】在平面直角坐标系中,过点,向圆:()引两条切线,则切线的长为∴以点为圆心,切线长为半径的圆的方程为∴直线的方程为,即∴令,得∴直线恒过定点故选B.12. 函数恰有一个零点,则实数的值为()A. B. C. D.【答案】D【解析】∵函数恰有一个零点∴方程在上有且只有一个根,即在上有且只有一个根令,则.当时,,则在上单调递减;当时,,则在上单调递增.∴由题意可知,若使函数恰有一个零点,则.故选D.点睛:利用函数零点的情况求参数值或取值范围的方法:(1)利用零点存在的判定定理构建不等式求解;(2)分离参数后转化为函数的值域(最值)问题求解;(3)转化为两熟悉的函数图象的上、下关系问题,从而构建不等式求解.第Ⅱ卷(共90分)二、填空题(每题5分,满分20分,将答案填在答题纸上)13. 在中,内角、、所对的边分别是、、,若,则的大小为__________.【答案】【解析】∵∴根据正弦定理可得∵∴,即∵∴故答案为.14. 已知向量,向量在向量方向上的投影为,且,则__________.【答案】【解析】设向量与间的夹角为.∵∴∵∴∵向量在向量方向上的投影为∴,即∴∴故答案为.15. 如图1,在矩形中,,,是的中点;如图2,将沿折起,使折后平面平面,则异面直线和所成角的余弦值为__________.【答案】【解析】取的中点为,连接,,延长到使,连接,,,则∥,所以为异面直线和所成角或它的补角.∵∴,且在中,根据余弦定理得.∴同理可得,又∵平面平面,平面平面,平面∴平面∵平面∴∴,即同理可得,又∵∴在中,∵两直线的夹角的取值范围为∴异面直线和所成角的余弦值为故答案为.点睛:对于异面直线所成的角,一般是通过平移的方法形成异面直线所成的角(或其补角),再根据其所在三角形的边角关系,计算其大小,要注意异面直线所成的角是锐角或直角,若计算出是钝角时,其补角才是异面直线所成的角.16. 对于实数,定义是不超过的最大整数,例如:.在直角坐标平面内,若满足,则的最小值为__________.【答案】2【解析】∵∴或者,即或∴表示的可行域如图所示:∵可以看作可行域内点到点距离的平方∴由图可知,可行域内的点到到点的距离的平方最小∴的最小值为2故答案为2.点睛:本题考查线性规划,点与点之间的距离公式以及新定义问题,属于难题. 新定义题型的特点是:通过给出一个新概念,或约定一种新运算,或给出几个新模型来创设全新的问题情景,要求考生在阅读理解的基础上,依据题目提供的信息,联系所学的知识和方法,实现信息的迁移,达到灵活解题的目的.解答本题的关键是理解新定义,画出正确的可行域.三、解答题(本大题共6小题,共70分.解答应写出文字说明、证明过程或演算步骤.)17. 已知数列满足,且.(1)求证:数列是等差数列,并求出数列的通项公式;(2)令,求数列的前项和.【答案】(1)见解析, (2)【解析】试题分析:(1)由可转化为,从而可证明数列是等差数列及数列的通项公式;(2)由(1)可得,利用错位相减法即可求出数列的前项和.试题解析:(1)∵,且,∴,即∴∴数列是等差数列∴,∴∴.(2)由(1)知,,,,,,.点睛:用错位相减法求和应注意的问题(1)要善于识别题目类型,特别是等比数列公比为负数的情形;(2)在写出“”与“”的表达式时应特别注意将两式“错项对齐”以便下一步准确写出“”的表达式;(3)在应用错位相减法求和时,若等比数列的公比为参数,应分公比等于1和不等于1两种情况求解.18. 某市县乡教师流失现象非常严重,为了县乡孩子们能接受良好教育,某市今年要为两所县乡中学招聘储备未来三年的教师,已知现在该市县乡中学无多余教师,为决策应招聘多少县乡教师搜集并整理了该市50所县乡中学在过去三年内的教师流失数,得到如表的频率分布表:以这50所县乡中学流失教师数的频率代替一所县乡中学流失教师数发生的概率.(1)求该市所有县乡中学教师流失数不低于8的概率;(2)若从上述50所县乡中学中流失教师数不低于9的县乡学校中任取两所调查回访,了解其中原因,求这两所学校的教师流失数都是10的概率.流失教师数45678910频数2411161232【答案】(1)0.34(2)【解析】试题分析:(1)由频数分布表即可求出教师流失数不低于8的概率;(2)教师流失数是9的三所学校分别记为,,,教师流失数是10的两所学校分别记为,,找出所有可能结果,代入古典概型概率计算公式,即可求解.试题解析:(1)由频数分布表可知教师流失数不低于8的概率为.(2)教师流失数是9的三所学校分别记为,,;教师流失数是10的两所学校分别记为,,从这5所学校中随机抽取2所,所有可能的结果共有10种,它们是,,,,,,,,,,又因为所抽取两所学校教师流失数都是10的结果有1种,即,故所求的概率为.19. 在如图所示的几何体中,,,平面,在平行四边形中,,,.(1)求证:平面;(2)求与平面所成角的正弦值.【答案】(1)见解析(2)【解析】试题分析:(1)连接交于,取中点,连接,,由中位线可得,,根据,,可推出,,即可证明平面;(2)连接,根据题设条件分别求出,,以及与,通过,可得,从而可求出点到平面的距离,通过解三角形即可求出与平面所成角的正弦值.试题解析:(1)证明:连接交于,取中点,连接,.∵、分别为、的中点∴,又∵,∴,,从而,平面,平面,∴平面.(2)解:连接,可计算得,,,,,设点到平面的距离为,则由,,得,所以由,知.∴,∴与平面所成角的正弦值为.20. 已知椭圆:的左、右焦点分别是、,离心率,过点的直线交椭圆于、两点,的周长为16.(1)求椭圆的方程;(2)已知为原点,圆:()与椭圆交于、两点,点为椭圆上一动点,若直线、与轴分别交于、两点,求证:为定值.【答案】(1) (2)见解析【解析】试题分析:(1)根据的周长为16,可得,再根据离心率,得出,从而可得椭圆的方程;(2)根据圆及椭圆的对称性可得,两点关于轴对称,设,,则,从而得出直线的方程,即可得到点的横坐标,同理可得点的横坐标,从而列出的表达式,化简求值即可得到定值.试题解析:(1)由题意得,则,由,解得,则,所以椭圆的方程为.(2)证明:由条件可知,,两点关于轴对称,设,,则,由题可知,,∴,.又直线的方程为,令得点的横坐标,同理可得点的横坐标.∴,即为定值.点睛:定点、定值问题通常是通过设参数或取特殊值来确定“定点”是什么、“定值”是多少,或者将该问题涉及的几何式转化为代数式或三角问题,证明该式是恒定的. 定点、定值问题同证明问题类似,在求定点、定值之前已知该值的结果,因此求解时应设参数,运用推理,到最后必定参数统消,定点、定值显现.21. 已知函数().(1)若函数在上单调递减,求实数的取值范围;(2)当时,试问方程是否有实数根?若有,求出所有实数根;若没有,请说明理由.【答案】(1) (2) 没有实数根【解析】试题分析:(1)求出函数的导数,设,根据函数在上单调递减,可得在上小于等于0恒成立,从而可得,即可得到实数的取值范围;(2)当时,,整理得,设,利用单调性求得;设,利用单调性求得,根据与在不同的值处取得,即可得到方程无实根.试题解析:(1)由题知,,设,∵函数在上单调递减∴在上小于等于0恒成立.∴解得∴实数的取值范围为.(2)没有实数根.当时,,整理得.设,则,当时,,则在上单调递减;当时,,则在上单调递增.∴.设,则,当时,,则在上单调递增;当时,,则在上单调递减,∴,∵与在不同的值处取得∴根据函数图象可知恒成立∴方程无实根.点睛:函数零点个数(方程根的个数)的判断方法:①结合零点存在性定理,利用函数的单调性、对称性确定函数零点个数;②利用函数图像交点个数判断方程根的个数或函数零点个数,本题将方程实根个数的问题转化为两函数图象交点的问题解决.请考生在22、23两题中任选一题作答,如果多做,则按所做的第一题记分.22. 选修4-4:坐标系与参数方程在直角坐标系中,直线的参数方程为(为参数),以坐标原点为极点,轴的正半轴为极轴建立极坐标系,并使得它与直角坐标系有相同的长度单位,曲线的极坐标方程为.(1)求直线的普通方程和曲线的直角坐标方程;(2)设曲线与直线交于、两点,且点的坐标为,求的值.【答案】(1),(2)9【解析】试题分析:(1)对直线的参数方程消参即可得直线的普通方程,根据即可得曲线的直角坐标方程;(2)将直线方程转化为标准形式的参数方程代入到曲线的直角坐标方程,结合韦达定理即可求出的值.试题解析:(1):,:,即,所以的普通方程是.(2)将直线方程转化为标准形式的参数方程:(为参数),代入中得:,.设,对应的参数分别为,,则,则.23. 选修4-5:不等式选讲已知函数.(1)求函数的最大值;(2)若,都有恒成立,求实数的取值范围.【答案】(1)3(2)【解析】试题分析:(1)由绝对值不等式的性质可得的最大值;(2),恒成立,等价于,即,对进行分类讨论,去绝对值,即可解得实数的取值范围.试题解析:(1),所以的最大值是3.(2),恒成立,等价于,即.当时,等价于,解得;当时,等价于,化简得,无解;当时,等价于,解得.综上,实数的取值范围为.点睛:本题考查绝对值不等式的解法,绝对值三角不等式的应用,考查基本不等式的应用.其中灵活应用分类讨论的思想是解题的关键.。
K12联盟2018届高三年级第一学期期末检测联考文科综合能力测试2018.2命审单位:安庆一中命审人:方卫和汪明山吴国华张昌东王中富陈金勇第I卷本卷共35小题,每小题4分,共140分。
在每小题给出的四个选项中,只有一项是最符合题目要求的。
读甲、乙两地生态系统的养分循环示意图(图1),回答l~2题。
1.甲地与乙地的土壤相比较A.甲、乙两地的土壤养分来源相同B.甲、乙两地的土壤有机质含量相同C.甲地的土壤比乙地肥沃D.甲、乙两地的土壤矿物质含量相同2.关于乙地发展农业生产的条件分析,正确的是A,全年高温多雨,雨热同期B.年均温较低,土壤有机质丰富C.地表径流丰富,水源充足D.地形平坦,土层较厚“潮汐车道”就是可变车道,是根据早晚交通流量的不同,将不同时段的行驶方向进行改变的车道。
图2为某城市西六路(鲁泰大道至兰雁大道路段)潮汐车道上的交通指示牌。
据此回答3—4题。
3.读某城市某条进出城主干道路上的交通量日变化图(图3),为了缓解交通拥堵问题可开通出城潮汐车道的时间段是A.t1~t2B.t2~t3C. t1~t3D.t3~t44.城市居民往返于居注地与各功能区之问所耗费的能量总和,为出行能耗。
读某大城市居民月出行次数与出行能耗的组合关系图(图4).下列甲、乙、丙、丁4个城市功能区与居住地最可能存在“潮汐车道”的是A.甲B.乙C.丙D.丁内河航运船舶航道的区位选择要根据水流的速度、泥沙沉积的实际情况而定,应尽可能实现节省能源、降低运费成本等效益最大化。
图5为某河流航运图。
依据图中信息,回答5~6题。
5.假如河流自东向西流,那么该河流域位于A.北半球B.南半球C.东半球D.西半球6.假如该图是长江上海一武汉航道,那么货船从武汉港装载50万吨钢材运往上海港时,选择的航道及其原因是A.A航道水流平稳,航运安全B.B航道河流含沙量小,阻力小C.A航道航道宽阔,水深流急D.B航道靠近河岸,基础设施完善2006-2010年期间,结合石漠化治理工程,在贵州喀斯特高原上设立了三类不同地理环境的石漠化治理示范区,进行了长期监测。
2017-2018学年安徽省安庆一中、山西省太原五中等五省六校(K12联盟)高三(上)期末数学试卷(理科)一、选择题:本大题共12个小题,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.(5分)若集合M={x|﹣2<x<3},N={x|2x+1≥1},则M∩N=()A.(3,+∞)B.(﹣1,3)C.[﹣1,3)D.(﹣2,﹣1] 2.(5分)(sin x+|sin x|)dx=()A.0B.1C.2D.33.(5分)已知复数z=x+yi(x,y∈R)满足,则y≥x﹣1的概率为()A.B.C.D.4.(5分)在二项式(x﹣)n的展开式中恰好第5项的二项式系数最大,则展开式中含x2项的系数是()A.﹣56B.﹣35C.35D.565.(5分)已知a>0,b>0,若不等式+≥恒成立,则m的最大值为()A.9B.12C.18D.246.(5分)函数f(x)=sinωx﹣cosωx(ω>0)在上单调递增,则ω的取值不可能为()A.B.C.D.7.(5分)执行如图所示的程序框图,如果输入的n=2017,则输出的S=()A.B.C.D.8.(5分)已知一个几何体的正视图、侧视图、俯视图如图所示,则该几何体的体积是()A.34B.22C.12D.309.(5分)已知双曲线C1:(a>0,b>0)的焦点为F1(0,﹣c),F2(0,c),抛物线C2:的准线与C1交于M、N两点,且MN与抛物线焦点的连线构成等边三角形,则椭圆的离心率为()A.B.C.D.10.(5分)本周日有5所不同的高校来我校作招生宣传,学校要求每位同学可以从中任选1所或2所去咨询了解,甲、乙、丙三位同学的选择没有一所是相同的,则不同的选法共有()A.330种B.420种C.510种D.600种11.(5分)圆C:x2+y2=2,点P为直线上的一个动点,过点P向圆C作切线,切点分别为A、B,则直线AB过定点()A.B.C.D.12.(5分)已知函数若存在x1,x2∈R,且x1≠x2,使f(x1)=f(x2),则实数a的取值范围为()A.a<2B.3<a<5C.a<2或3<a<5D.2≤a≤3或a≥5二、填空题(每题5分,满分20分,将答案填在答题纸上)13.(5分)在△ABC中,内角A、B、C所对的边分别是a、b、c,若,则∠C的大小为.14.(5分)已知向量,向量在向量方向上的投影为,且,则=.15.(5分)如图1,在矩形ABCD中,AB=2,BC=1,E是DC的中点;如图2,将△DAE 沿AE折起,使折后平面DAE⊥平面ABCE,则异面直线AE和DB所成角的余弦值为.16.(5分)若函数,若对任意不同的实数x1、x2、x3,不等式f(x1)+f(x2)>f(x3)恒成立,则实数m的取值范围为.三、解答题(本大题共5小题,共70分.解答应写出文字说明、证明过程或演算步骤.)17.(12分)已知数列{a n}满足,a n≠﹣1且a1=1.(1)求证:数列是等差数列,并求出数列{a n}的通项公式;(2)令b n=a n+1,,求数列{c n}的前2018项和S2018.18.(12分)在如图所示的几何体中,PB∥EC,PB=2CE=2,PB⊥平面ABCD,在平行四边形ABCD中,AB=1,AD=2,∠BAD=60°.(1)求证:AC∥平面PDE;(2)求二面角A﹣PE﹣D的余弦值.19.(12分)某市县乡教师流失现象非常严重,为了县乡孩子们能接受良好教育,某市今年要为两所县乡中学招聘储备未来三年的教师,现在每招聘一名教师需要1万元,若三年后教师严重短缺时再招聘,由于各种因素,则每招聘一名教师需要3万元,已知现在该市县乡中学无多余教师,为决策应招聘多少县乡教师搜集并整理了该市50所县乡中学在过去三年内的教师流失数,得到如表的频率分布表:以这50所县乡中学流失教师数的频率代替一所县乡中学流失教师数发生的概率,记X表示两所县乡中学在过去三年共流失的教师数,n表示今年为两所县乡中学招聘的教师数.为保障县乡孩子教育不受影响,若未来三年内教师有短缺,则第四年马上招聘.(1)求X的分布列;(2)若要求P(X≤n)≥0.5,确定n的最小值;(3)以未来四年内招聘教师所需费用的期望值为决策依据,在n=15与n=16之中选其一,应选用哪个?20.(12分)已知直线l:与圆x2+y2=5相交的弦长等于椭圆C:(0<b<3)的焦距长.(1)求椭圆C的方程;(2)已知O为原点,椭圆C与抛物线y2=2px(p>0)交于M、N两点,点P为椭圆C 上一动点,若直线PM、PN与x轴分别交于G、H两点,求证:|OG|•|OH|为定值.21.(12分)已知函数f(x)=e x﹣a(x﹣1)有两个零点.(1)求实数a的取值范围;(2)设x1,x2(x1<x2)是f(x)的两个零点,证明:x1•x2<x1+x2.请考生在22、23两题中任选一题作答,如果多做,则按所做的第一题记分.[选修4-4:坐标系与参数方程]22.(10分)在直角坐标系xOy中,直线l的参数方程为(t为参数),以坐标原点为极点,x轴的正半轴为极轴建立极坐标系,并使得它与直角坐标系xOy有相同的长度单位,曲线C的极坐标方程为ρ=4sinθ.(1)求直线l的普通方程和曲线C的直角坐标方程;(2)设曲线C与直线l交于A、B两点,且M点的坐标为(3,4),求|MA|•|MB|的值.[选修4-5:不等式选讲]23.已知函数f(x)=|x﹣2|﹣|x+1|.(1)求函数f(x)的最大值;(2)若∀x∈R,都有4f(x)≤|2m﹣1|+|m+5|恒成立,求实数m的取值范围.2017-2018学年安徽省安庆一中、山西省太原五中等五省六校(K12联盟)高三(上)期末数学试卷(理科)参考答案与试题解析一、选择题:本大题共12个小题,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.【解答】解:∵集合N={x|2x+1≥1}={x|2x+1≥20}={x|x+1≥0}={x|x≥﹣1},集合M={x|﹣2<x<3},∴M∩N={x|﹣2<x<3}∩{x|x≥﹣1}={x|﹣1≤x<3},故选:C.2.【解答】解:(sin x+|sin x|)dx=(2sin x)dx+dx=﹣2cos x|=2,故选:C.3.【解答】解:复数z=x+yi(x,y∈R)满足,它的几何意义是以(0,0)为圆心,1为半径的圆以及内部部分.y≥x﹣1的图形是除去图形中阴影部分,如图:复数z=x+yi(x,y∈R)满足,则y≥x﹣1的概率:=.故选:C.4.【解答】解:∵在二项式(x﹣)n的展开式中恰好第5项的二项式系数最大,∴n=8,展开式的通项公式为T r+1==•(﹣1)r•x8﹣2r,令8﹣2r=2,则r=3,∴展开式中含x2项的系数是﹣=﹣56.5.【解答】解:∵a>0,b>0,不等式+≥恒成立,∴.∵=6+=12,当且仅当a=3b时取等号.∴m的最大值为12.故选:B.6.【解答】解:∵f(x)=sin(ωx﹣)(ω>0)由﹣+2kπ≤ωx﹣≤+2kπ,k∈Z得﹣+≤x≤+,k∈Z依题意得:,解得,∴0,故选:D.7.【解答】解:根据题意得,S=++…+=(1﹣+﹣+…+)=(1﹣)=.故选:B.8.【解答】解:根据三视图知,该几何体是三棱锥P﹣ABC,把该三棱锥放入棱长为6的正方体中,如图所示;根据图中数据,计算△ABC的面积为S△ABC=62﹣×3×4﹣×4×2﹣×(2+3)×6=11,所以该几何体的体积是V=S△ABC•h=×11×6=22.9.【解答】解:抛物线C2:的准线方程为y=﹣c,焦点坐标为(0,c)由,解得x=±,则MN=,∵MN与抛物线焦点的连线构成等边三角形,∴=tan60°=,∴2ac=b2=(c2﹣a2),即2e=(e2﹣1),解得e=,∴=,∴c=∴椭圆的离心率为=故选:D.10.【解答】解:由题意,若都选1所,有A53=60种;若有1人选2所,则有C31C52A33=180种,若有2人选2所,则有C32C52C32=90种,故共有60+180+90=330种,故选:A.11.【解答】解:∵P是直线6x+3y﹣18=0的任一点,∴设P(3﹣,m),∵圆x2+y2=2的两条切线P A、PB,切点分别为A、B,∴OA⊥P A,OB⊥PB,则点A、B在以OP为直径的圆上,即AB是圆O和圆C的公共弦,则圆心C的坐标是(,),且半径的平方是r2=()2+,圆C的方程是[x﹣()]2+(y﹣)2=()2+,①又x2+y2=2,②,②﹣①得6x﹣4﹣m(x﹣2y)=0,即公共弦AB所在的直线方程是:6x﹣4﹣m(x﹣2y)=0,由,得x=,y=,∴直线AB恒过定点(,),故选:B.12.【解答】解:当a=0时,当x≤1时,f(x)=﹣x2,当x>1时,f(x)=14,此时存在当x∈[﹣1,1]时,满足条件.若a>0,则当x>1时,f(x)为增函数,且f(x)>a2﹣7a+14,当x≤1时,f(x)=﹣x2+ax=﹣(x﹣)2+,对称轴为x=,若<1即a<2时,则满足条件,若≥1,即a≥2时,函数在(﹣∞,1]上单调递增,要使条件成立则f(x)在(﹣∞,1]上的最大值f(1)=﹣1+a>a2﹣7a+14,即a2﹣8a+15<0,即3<a<5,∵a≥2,∴3<a<5,综上3<a<5或a<2,故选:C.二、填空题(每题5分,满分20分,将答案填在答题纸上)13.【解答】解:∵,∴由正弦定理可得:=2sin C,∵由余弦定理可得:cos C=,可得:cos C=sin C,∴tan C=,∵C∈(0,π),∴C=.故答案为:.14.【解答】解:向量,向量在向量方向上的投影为,∴||•cos<,>=2.∵,∴﹣2+=10,即5﹣2••2+=10,∴=25,则=5,故答案为:5.15.【解答】解:由题意,过D作DM垂直AE于M,连接BM,BC与EB交于O,过O作BD的平行线,交DE于N,可得直线AE和DB所成角的平面角为∠FON,(如图)平面DAE⊥平面ABCE,AD=DE,∴DM⊥AE,DM⊥平面ABCE,且AM=DM=,则BM2=△DMB是直角三角形.∴DB2=4∵DB∥ON,∴ON=2,过N作AE垂下交于G.接连FG,∴NG=DM=.在△AFG中,余弦定理可得GF2=△NFG是直角三角形.∴NF2=OF=.在△NFO中,由余弦定理,可得cos∠FON=.故答案为:16.【解答】解:函数,可化为f(x)=,令t=(t≥3),则f(x)=y=1+,若m﹣1<0,即m<1,函数y=1+,在[3,+∞)上为增函数,此时的函数f(x)=y值域为[1+,1),若不等式f(x1)+f(x2)>f(x3)恒成立,则2(1+)≥1,就可以满足条件,解得:1,若m﹣1=0,即m=1,f(x)=1,不等式f(x1)+f(x2)>f(x3)显然成立若m﹣1>0,即m>1函数y=1+在[3,+∞)上为减函数此时的函数f(x)=y值域为(1,1+]若不等式f(x1)+f(x2)>f(x3)恒成立则1+1≥1+,解得1<m≤4综上所述:m≤4故答案为:三、解答题(本大题共5小题,共70分.解答应写出文字说明、证明过程或演算步骤.)17.【解答】证明:(1),a n≠﹣1且a1=1,∴,即,∴,数列是等差数列,∴,∴,∴.解:(2)由(1)知,∴=,∴∁n=(﹣1)n﹣1(+),∴S2018=(1+)﹣(+)+(+)+…﹣(+)=.18.【解答】(1)证明:连接BD交AC于O,取PD中点F,连接OF,EF,∵OF∥PB,,又PB∥CE,,∴OF∥CE,OF=CE,则四边形OCEF为平行四边形,从而AC∥EF,∵AC⊄平面PDE,EF⊂平面PDE,∴AC∥平面PDE;(2)解:在平行四边形ABCD中,由AD=2,AB=1,∠BAD=60°,得BD2=AB2+AD2﹣2AB•AD•cos60°=,∴AB2+BD2=AD2,则AB⊥BD,又PB⊥平面ABCD,∴PB⊥BA,PB⊥BD,以B为原点,分别以,,的方向为x轴,y轴,z轴的正方向建立空间直角坐标系B﹣xyz,则B(0,0,0),A(1,0,0),,P(0,0,2),,则,,,设平面P AE的一个法向量为,则由,得,令,得,,设平面PDE的一个法向量为,则由,得,令,得,,∴,∴所求二面角的余弦值为.19.【解答】解:(1)由频数分布表中教师流失频率代替教师流失概率可得,一所县乡中学在三年内流失的教师数为6,7,8,9的概率分别为0.2,0.3,0.3,0.2.X所有可能的取值为:12,13,14,15,16,17,18,且,,,,,,,所以X的分布列为:(2)由(1)知P(X≤14)=0.37,P(X≤15)=0.63,故n的最小值为15.(3)记Y表示两所县乡中学未来四年内在招聘教师上所需的费用(单位:万元).当n=15时,Y的分布列为:E(Y)=15×0.63+18×0.21+21×0.12+24×0.04=16.71;当n=16时,Y的分布列为:E(Y)=16×0.84+19×0.12+22×0.04=16.6.可知当n=16时所需费用的期望值小于n=15时所需费用的期望值,故应选n=16.20.【解答】解:(1)由题意知,圆心(0,0)到直线的距离为,圆的半径为,直线与圆相交的弦长为,则2c=4,c=2,又∵a2=9,∴b2=a2﹣c2=9﹣4=5,∴椭圆C的方程.(2)证明:由条件可知,M,N两点关于x轴对称,设M(x1,y1),P(x0,y0),则N (x1,﹣y1),由题可知,,,所以,.又直线PM的方程为,令y=0得点G的横坐标,同理可得H点的横坐标,所以|OG|•|OH|=|•|=||==9,即|OG|•|OH|为定值.21.【解答】解:(1)∵f'(x)=e x﹣a,x∈R.①当a≤0时,f'(x)>0在R上恒成立,∴f(x)在R上单调递增,显然不符合题意.②当a>0时,由f'(x)=0,得x=lna,当x→+∞,x→﹣∞时都有f(x)→+∞,当f(lna)=a(2﹣lna)<0,即a>e2时f(x)有两个零点.(2)要证x1x2<x1+x2,即证(x1﹣1)(x2﹣1)<1,由已知,,即证,即证,即证x1+x2<2lna,即证x2<2lna﹣x1,又∵x2>lna,且f(x)在(lna,+∞)单调递增,故只需证f(x2)<f(2lna﹣x1),即证f(x1)<f(2lna﹣x1),令g(x)=f(2lna﹣x)﹣f(x)且x<lna,∵==,∴g(x)在(﹣∞,lna)单调递减,∴g(x)>g(lna)=f(2lna﹣lna)﹣f(lna)=0,∴f(2lna﹣x)>f(x)在(﹣∞,lna)上恒成立,∴f(2lna﹣x1)>f(x1),故原命题得证.请考生在22、23两题中任选一题作答,如果多做,则按所做的第一题记分.[选修4-4:坐标系与参数方程]22.【解答】解:(1)直线l的参数方程为(t为参数),转换为直角坐标方程为:x﹣y+1=0,曲线C的极坐标方程为ρ=4sinθ.转换为:ρ2=4ρsinθ,即x2+y2=4y,所以C的普通方程是x2+(y﹣2)2=4.(2)将直线方程转化为标准形式的参数方程l:(t为参数),代入x2+(y﹣2)2=4中,得:,△=50﹣36=14>0,设A,B对应的参数分别为t1',t2',则t1't2'=9,则|MA|•|MB|=|t1'||t2'|=9.[选修4-5:不等式选讲]23.【解答】解:(1)f(x)=|x﹣2|﹣|x+1|≤|x﹣2﹣(x+1)|=3,所以f(x)的最大值是3.(2)∀x∈R,4f(x)≤|2m﹣1|+|m+5|恒成立,等价于4f(x)max≤|2m﹣1|+|m+5即|2m﹣1|+|m+5|≥12.当m<﹣5时,等价于﹣(2m﹣1)﹣(m+5)≥12,解得;当时,等价于﹣(2m﹣1)+(m+5)≥12,化简得m≤﹣6,无解;当时,等价于2m﹣1+m+5≥12,解得.综上,实数m的取值范围为.。
安徽省五省六校(K12联盟)2018届高三上学期期末联考英语试题第一部分听力(共两节,满分30分)做题时,先将答案标在试卷上。
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听完每段对话后,你都有10秒钟的时间来回答有关小题和阅读下一小题。
每段对话仅读一遍。
1. Where does the conversation probably take place?A. In a bookstore.B. In a library.C. In a classroom.2. What are the speakers doing?A. Doing shopping.B. Designing clothes.C. Getting dressed.3. What does the man mean?A. He’ll move the boxes for the woman.B. He wants Bob to give him a hand.C. He can’t help the woman.4. What does the man think of the seals in Prestige Air’s planes?A. Small.B. Wide.C. Comfortable.5. What are the speakers mainly talking about?A. The man’s early projects.B. The woman’s term paper.C. The way to write a paper.第二节(共15小题;每小题1.5分,满分22.5分)听下面5段对话或独白,每段对话或独白后有几个小题,从题中所给的A、B、C三个选项中选出最佳选项,并标在试卷的相应位听每段对话或独白前,你将有时间阅读各个小题,每小题5秒钟;听完后,各小题将给出5秒钟的作答时间。
江西省六校2018届高三数学上学期第五次联考试题 理(含解析)第I 卷(选择题)一、本大题共12小题,每题5分,共60分1.集合1{|()1},{|lg(2)}2xM x N x y x =≥==+,则M N ⋂等于( ) A. [)0,+∞B. (]2,0-C. ()2,-+∞D.()[),20,-∞-+∞U【答案】B 【解析】试题分析:Q 集合0111|1|222x x M x x ⎧⎫⎧⎫⎪⎪⎪⎪⎛⎫⎛⎫⎛⎫=≥=≥⎨⎬⎨⎬ ⎪ ⎪ ⎪⎝⎭⎝⎭⎝⎭⎪⎪⎪⎪⎩⎭⎩⎭,{}|0M x x ∴=≤,(){}{}|lg 2|2N x y x x x ==+=>-,{}{}{}|0|2|20A B x x x x x x ∴⋂=≤⋂>-=-<≤,故选B.考点:指数函数、对数函数的性质及集合的运算.2.已知函数()f x 是R 上的奇函数,当0x >时为减函数,且(2)0f =,则{}(2)0x f x -<=( )A. {}024x x x <或 B. {}04x x x 或C. {}022x x x <或D. {}0224x x x <<<<或【答案】A 【解析】∵奇函数满足f (2)=0, ∴f (−2)=−f (2)=0.对于{x |f (x −2)>0},当x −2>0时,f (x −2)>0=f (2), ∵x ∈(0,+∞)时,f (x )为减函数, ∴0<x −2<2, ∴2<x <4.当x −2<0时,不等式化为f (x −2)<0=f (−2),∵当x ∈(0,+∞)时,f (x )为减函数, ∴函数f (x )在(−∞,0)上单调递减, ∴−2<x −2<0,∴0<x <2.综上可得:不等式的解集为{x ∣∣0<x <2或2<x <4} 故选D.3.给出下列四个命题:①“若0x 为()y f x =的极值点,则()'00f x =”的逆命题为真命题;②“平面向量a r ,b r 的夹角是钝角”的充分不必要条件是0a b r rg <③若命题1:01p x >-,则1:01p x ⌝≤- ④命题“0x R ∃∈,使得210x x ++≤”的否定是:“x R ∀∈均有012≥++x x ”. 其中不正确的个数是 A. 1B. 2C. 3D. 4【答案】C 【解析】 【分析】①先写出原命题的逆命题,再判真假;②向量点积小于零,夹角为钝角或平角;③先求出命题p 所对应的x 的取值范围,再求它相对于R 的补集,即为命题p ⌝所对应x 的范围;④特称命题的否定为全称命题。
安徽省五省六校(K12联盟)2018届高三联考英语试题第二部分阅读理解(共两节,满分40分)(注:山西考生,满分60分)第一节(共15小题;每小题2分,满分30分)(注:山西考生,每小题3分,满分45分)阅读下列短文,从所给的四个选项(A、B、C、D)中选出最佳选项,并在答题卡上将选项涂黑。
AAs fun and enriching as traveling can be, it can also prove to be very expensive. That’s why we’ve rounded up a list of the best international destinations to go to in 2018 that won’t break the bank.LaosLocated in Southeast Asia, Laos is an underrated country with a ton to offer, ill ere is an abundance of French colonial architecture, stunning Buddhist monasteries (修道院), jungles, and the nicest locals. The best part is it’s not super touristy, so you won’t be subje ct to jacked up prices or overwhelming crowds.For local meals and street eats, you can expect to pay $2 to $4, while a gourmet (精美的) meal with drinks will cost you $ 15 to $ 50. You can even get a boutique hotel or resort for us low as $ 50.PortugalPortugal is certainly having a moment right now, with tourists flocking to the Southern European country that borders Spain. Here you’ll find major cities filled with culture, stunning beaches, picturesque landscapes, sensational cuisine, and port wine.You can get a basic hotel starting from about $ 35, or a boutique hotel starting from about $ 120. As far as food, you can get a lunch special al a family-run restaurant for $ 8 to $ 12, and dinner for two in a top restaurant for $ 92.NicaraguaAnother country where tourism has yet to boom, this Central American country is set between the Pacific Ocean and the Caribbean Sea and is best known for its lakes, volcanoes, and beaches. Because Nicaragua isn’t quite on everyone’s radar just yet, you can expect low p rices. Go during the rainy season, and you can expect even a 20% discount.A typical meal will cost you $4, a gourmet meal $20, and a double bed in a luxury hotel will cost you between $ 80 to $ 120.21. Where could you go to enjoy tropical jungles?A. LaosB. PortugalC. SpainD. Nicaragua22. Visiting Nicaragua in the rainy season, for a gourmet meal you will pay ?A. $ 4.B. $8.C. $ 16.D. $20.23. What do these destinations have in common according to the text?A. They are European countries.B. Tourists can spend less money.C. They are underdeveloped countries.D. Tourists can enjoy living by the sea.BWhatever Rock was doing down there, it made enough noise for me to go to him. By the time I made it to the bottom of the stairs, he was running up, and he never came up the stair, no matter what. I think that was his way of telling me, “We’ve got to go back up.”When I got to the top of the stairs, I turned around and saw a light on, but I didn’t remember leaving one on. I walked downstairs again, and that’s when I saw fire. I immediately should to my wife to wake up and get our three kids. I grabbed a knife and cut out the plastic that covered the window to the porch roof. I then broke the window and kicked out the screen. I got everybody out on the roof and threw a blanket out there so we wouldn’t slip off. It was cold, January cold. Then I started screaming for help. But help never came.Now, I’m scared of heights and have physica l issues, what with my rheumatoid arthritis (类风湿性关节炎), but I couldn’t let ray family bum up. So I jumped off the roof. I didn’t run to the edge, I just jumped and got the wind knocked out of me when I landed.I found our ladder, placed it against the house, and climbed back up to the roof. I wrapped my arms around my daughter and canned my nine-month-old with my teeth, by his little sleeper. Then I climbed down the ladder. Once on ground, I had my little girl hold her brother, and I went back up to the roof lo get my other daughter. Then I went back up again and got my wife. I tried to get my dog, but he just disappeared in the black smoke. I never saw him alive again.I’m no hero. I’m just an ordinary person who’d help anybody. This happened to be the ti me when I helped my own family. I live to protect my family. Just like Rock — he lived lo protect us.24. Why did Rock make enough noise?A. Rock caused the fire and tried to escape.B. Rock was warming up itself to fight cold.C. Rock was playing upstairs and downstairs.D. Rock tried to remind the author of the fire.A. to call for helpB. to challenge himselfC. to find tools for rescueD. to escape being burned26. What can we learn about the author?A. Strict and devoted.B. Smart and sociable.C. Responsible and brave.D. Powerful and considerate.27. Which of the following can be the best title of the text?A. Rock’s Heroic LifeB. Escape from the FireC. A Lesson I Have LearntD. My Adventure ExperienceCIf you’re a commuter (通勤者) or drive on the highway often, you’ve probably seen those tall wall-like structures alongside the road. You may think they’re there to pr event cars and trucks from going off the road, or to provide privacy nearby neighborhoods. But that’s actually not their main purpose.It all started back when the 1958 Hollywood Bowl was drowned out by nearby highway noise. Ever since, tall barriers made out of noise-cancelling materials were construct along the busiest areas of America’s highways to prevent the noise from affecting surrounding areas. There are now 2,748 miles of these walls across the U.S.According to the Federal Highway Administration, barrier walls can reduce highway noise by almost half. The structures are typically made out of wood, concrete or brick-materials that absorb or reduce sound.The critical aspect of the construction of these walls is their height. They’re built high en ough to be over the line of sight, usually much taller than any car or truck. Building them up this high reduces sound waves by about 5-10 decibels. Human ears can’t usually notice a difference below 3 decibels, so the taller the better!The barriers are most effective when they are built within 61 meters of the road, which is why they can seem like safety barriers. They also cannot have any openings, or else the noise will leak through and the wall will be ineffective.The FWHA also puts aesthetic standa rds on the noise reducing walls. They “must be designed to be visually appealing and must be designed to preserve aesthetic values and scenic views,” according to the organization’s website. This is done to keep the natural landscape that typically surrounds highways complete and make them pleasant for surrounding residential communities as well.28. What’s the main purpose of tall walls according to the text?A. To keep wildlife away from the road.B. To prevent cars from going off the road.C. To provide privacy to nearby neighborhoods.D. To prevent the noise from disturbing surroundings.29. What is the vital aspect of tall walls according to the text?A. the heightB. the materialC. the placeD. the style30. What can we learn about safety barriers according to the text?A. They were built since 1958.B. They are made from wood, or concrete.C. They stand within 61 meters of the road.D. They are built at a similar height of tall walls.31. What does the underlined word “aesthetic” in Para. 6 mean?A. noisy B artistic C. typical D. naturalDHomeless people face a lot of challenges. Some of the most basic challenges, however, spring from not having regular access to clean water and cleaning stuff such as soap and shampoo. And poor personal hygiene (卫生) can he particularly troubling for homeless teens.That challenge inspired a young researcher, Leia Glunckman, to invent a multi-purpose product. It would need to absorb sweat and oil from skin and hair. It would need to clean teeth. Plus, it would need to kill bacteria without being harmful to people. She wanted her ingredients to be natural and biodegradable (可降解的).Leia started by going to stores and looking at I he ingredient (原料) lists for tooth powders, body powders and dry shampoos. Then she put together eight different trial recipes of her own. She tested each mixture to see how well it absorbed body oil and cleaned hair, to find out how these might work as a toothpaste, she tested them al removing coffee stains from eggshells.Eventually, Leia settled on three working recipes. Each contains salt and baking powder. The salt helps clean teeth and remove dirt, she notes. Baking powder helps absorb smells. Her three recipes’ other ingredients di ffer. Some of those ingredients included cloves, cinnamon and chamomile. Those sorts of things give her products different tastes and smells. That would let teens choose a product based on personal preferences.Leia wants to develop her products further. “Could it be used to drive off mosquitoes?” she asks. “Or does it attract them? These are questions I want to answer next,” she notes.Science offers a way to go about “solving problems and helping people,” says Leia. And she thinks her products could benefit a broad range of people, not just the homeless. Anyone in an area with little or no access to clean water could find her products useful, she says.32. What made Leia make the product according to the text?A. Her personal experience.B. The suffering of homeless people.C. Poor personal hygiene for homeless people.D. Her curiosity about invention and helping others.33. The third paragraph mainly tells us .A. How Leia made the productB. how effective the product isC. what functions the product hasD. what ingredients the product has34. What can we learn about the product from the fourth paragraph?A. People can buy it in the market now.B. The product only has three varieties.C. Salt is used lo clear smells and remove dirt.D. It can be custom-made to suit personal taste.35. How does Leia feel about her invention?A. It has some faults.B. It is quite satisfactory.C. It still needs improving.D. It is useful in remote area.第二节(共5小题;每小题2分,满分10分)(注:山西考生,每小题3分,满分15分)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。
2018年江西省六校高三联考理科数学试题一、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. 设全集是实数集,函数的定义域为,,则=()A. B. C. D.【答案】D【解析】,所以,选D.2. 复数的共轭复数记作,已知复数对应复平面上的点,复数满足,则()A. B. C. D.【答案】A【解析】,选A.3. 我国古代名著《九章算术》用“更相减损术”求两个正整数的最大公约数是一个伟大创举,这个伟大创举与我国古老的算法—“辗转相除法”实质一样.如图的程序框图源于“辗转相除法”,当输入,时,输出的()A. 30B. 6C. 2D. 8【答案】C【解析】执行循环得:,结束循环,输出,选C.4. 下列命题中:(1)“”是“”的充分不必要条件(2)定义在上的偶函数最小值为5;(3)命题“,都有”的否定是“,使得”(4)已知函数的定义域为,则函数的定义域为.正确命题的个数为()A. 1个B. 2个C. 3个D. 4个【答案】C【解析】(1) ,所以“”是“”的充分不必要条件;(2)为偶函数,所以,因为定义区间为,所以,因此最小值为5;(3) 命题“,都有”的否定是“,使得”;(4)由条件得;因此正确命题的个数为(1)(2)(4),选C.5. 在内随机地取一个数,则事件“直线与圆有公共点”发生的概率为()A. B. C. D.【答案】A【解析】若直线与圆有公共点,则因此概率为,选A6. 一个四棱锥的三视图如图所示,则其体积为()A. 11B. 12C. 13D. 16【答案】D【解析】几何体如图,则体积为,选D.点睛:空间几何体体积问题的常见类型及解题策略(1)若所给定的几何体是可直接用公式求解的柱体、锥体或台体,则可直接利用公式进行求解.(2)若所给定的几何体的体积不能直接利用公式得出,则常用转换法、分割法、补形法等方法进行求解.(3)若以三视图的形式给出几何体,则应先根据三视图得到几何体的直观图,然后根据条件求解.7. 已知在各项为正数的等比数列中,与的等比中项为4,则当取最小值时,等于()A. 32B. 16C. 8D. 4【答案】B【解析】设各项为正数的等比数列的公比为∵与的等比中项为4∴∴∴当且仅当,即时取等号,此时故选A8. 设满足约束条件,若目标函数的取值范围恰好是的一个单调递增区间,则的一个值为()A. B. C. D.【答案】D【解析】作出不等式组对应的平面区域如图:则z的几何意义为区域内的点D(﹣2,0)的斜率,由图象知DB的斜率最小,DA的斜率最大,由,即A(﹣1,2),则DA的斜率k DA=2,由即B(﹣1,﹣2),则DB的斜率k DB=-2,则﹣2≤z≤2,故的取值范围是[﹣2,2],故[﹣2,2]是函数的一个单增区间,故故得到答案为C。
第 1 页 共 13 页K12联盟2018届高三年级第一学期期末检测联考数学(理科试题)第Ⅰ卷(共60分)一、选择题:本大题共12个小题,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.若集合{}|23M x x =-<<,{}1|21x N x +=≥,则MN =( ) A .(3,)+∞B .(1,3)-C .[1,3)-D .(2,1]-- 2.22(sin |sin |)x x dx ππ-+=⎰( ) A .0 B .1 C .2 D .33.已知复数z x yi =+(x ,y R ∈)满足||1z ≤,则1y x ≥+的概率为( )A .3142π- B .1142π- C .3142π+ D .1142π+ 4.在二项式1()n x x -的展开式中恰好第5项的二项式系数最大,则展开式中含有2x 项的系数是( )A .35B .35-C .56-D .565.已知0a >,0b >,若不等式313m a b a b +≥+恒成立,则m 的最大值为( ) A .9 B .12C .18D .24 6.函数()sin cos (0)f x x x ωωω=->在(,)22ππ-上单调递增,则ω的取值不可能为( ) A .14B .15C .12D .34 7. 执行如图所示的程序框图,如果输入的2017n =,则输出的S =( )A .40344035B .20174035C .40364037D .20184037第 2 页 共 13 页8.已知一个几何体的正视图、侧视图、俯视图如图所示,则该几何体的体积是( )A .34B .22C .12D .30 9.已知双曲线1C :22221y x a b-=(0a >,0b >)的焦点为1(0,)F c -,2(0,)F c ,抛物线2C :214y x c=的准线与1C 交于M 、N 两点,且MN 与抛物线焦点的连线构成等边三角形,则椭圆22221x y a c+=的离心率为( ) A.3 BCD10.本周日有5所不同的高校来我校作招生宣传,学校要求每位同学可以从中任选1所或2所去咨询了解,甲、乙、丙三位同学的选择没有一所是相同的,则不同的选法共有( )A .330种B .420种C .510种D .600种 11.圆C :222x y +=,点P 为直线136x y +=上的一个动点,过点P 向圆C 作切线,切点分别为A 、B ,则直线AB 过定点( ) A .11(,)23 B .21(,)33 C .11(,)32 D .12(,)3312.已知函数22,1,()714,1,x ax x f x a x a x ⎧-+≤⎪=⎨-+>⎪⎩若存在1x ,2x R ∈,且12x x ≠,使12()()f x f x =,则实数a 的取值范围为( )A .2a <B .35a <<C .2a <或35a <<D .23a ≤≤或5a ≥第Ⅱ卷(共90分)二、填空题(每题5分,满分20分,将答案填在答题纸上)13.在ABC ∆中,内角A 、B 、C 所对的边分别是a 、b 、c,若sin sin sin sin a A b B c C C a B+-=,则C ∠的大小为 . 14.已知向量(1,2)a =,向量b 在向量a方向上的投影为||10a b -=,则||b = .15.如图1,在矩形ABCD 中,2AB =,1BC =,E 是DC 的中点;如图2,将D AE ∆沿。
南昌市第二中学2018届高三上学期第五次月考数学(理)试题一、选择题(每小题5分,共60分。
每小题所给选项只有一项符合题意,请将正确答案的选项填涂在答题卡上)1.已知集合{|lg }A x y x ==, 2{|230}B x x x =--<,则A B ⋂=( ) A. ()0,3B. ()1,0-C. ()(),03,-∞⋃+∞D. ()1,3-2. 已知()3z +⋅=-(i 是虚数单位),那么z 的共轭复数对应的点位于复平面内的( ) A. 第一象限B. 第二象限C. 第三象限D. 第四象限3. 若l 、n 是互不相同的空间直线,α、β是不重合的平面,则下列命题中为真命题的是( ) A. 若//,,l n αβαβ⊂⊂,则//l n B. 若,l αβα⊥⊂,则l β⊥ C. 若//,,l ααβ⊥则l β⊥D. 若,//l l αβ⊥,则αβ⊥4.已知等差数列{}n a 的前n 项和为34,3,10n S a S ==,则数列1n S ⎧⎫⎨⎬⎩⎭的前100项的和为( ) A.200101B.100101C.1101D.21015. 若0,0x y >>,且280x y xy +-=,则xy 的最小值为( ) A. 8B. 14C. 16D. 646.D 是ABC ∆所在平面内一点, (),AD AB AC R λμλμ=+∈,则01,01λμ<<<<是点D 在ABC ∆内部(不含边界)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7. 已知ABC ∆的三个内角,,A B C 的大小依次成等差数列,角,,A B C 的对边分别是,,a b c ,并且函数()22f x ax x c =++的值域是[)0,+∞,则ABC ∆的面积是 ( )A.4B.2C.3D.8. 某几何体的三视图如图所示,则该几何体的表面积是( )A. 2B.52C. 3D.7229. 设0.60.6a =, 1.50.6b =, 0.61.5c =,则,,a b c 的大小关系是( )A. a b c <<B. a c b <<C. b a c <<D. b c a <<10.已知函数()y f x =是定义域为R 的偶函数. 当0x ≥时,5sin() (01)42()1() 1 (1)4x x x f x x π⎧≤≤⎪⎪=⎨⎪+>⎪⎩.若关于x 的方程2[()]()0f x af x b ++=(,a b R ∈),有且仅有6个不同实数根,则实数a 的取值范围是( ) A .59(,)24--B .9(,1)4-- C .599(,)(,1)244----D .5(,1)2--11. 已知函数()f x 是定义在()0,+∞的可导函数, ()'f x 为其导函数,当0x >且 1x ≠ 时,()()2'01f x xf x x +>-,若曲线()y f x =在1x =处的切线的斜率为34-,则 ()1f =( ) A. 0B. 1C. 38D.1512.已知a 为常数,函数()()ln f x x x ax =-有两个极值点1212,()x x x x <,则( ) A. ()()1210,2f x f x >>-B. ()()1210,2f x f x <<-C. ()()1210,2f x f x ><-D. ()()1210,2f x f x <>-二、填空题(每小题5分,共20分,把答案填写在答题纸的相应位置上)13. 在等比数列{}n a 中, 23a a ==112011172017a a a a +=+__________.14. 在平面内,···6AB AC BA BC CACB ===,若动点,P M 满足2,AP PM MC ==,则BM 的最小值是__________.15. 已知区域2:2010y D x y x y ≥⎧⎪+-≥⎨⎪--≤⎩,则圆()()22:22C x a y -+-=与区域D 有公共点,则实数a 的取值范围是__________.16. 在三棱锥S ABC -中, ABC ∆是边长为3的等边三角形,SA SB =S AB C --的大小为120°,则此三棱锥的外接球的表面积为__________.三、解答题(本大题共70分=10分+12×5分,解答应写出文字说明,证明过程或演算步骤) 17. (本题满分10分)在ABC ∆中,内角A ,B ,C 的对边分别为a ,b ,c ,已知C B C C B B cos cos 4)cos sin 3)(cos sin 3(=--.(Ⅰ)求角A 的大小;(Ⅱ)若C p B s i n s i n =,且AB C ∆是锐角三角形,求实数p 的取值范围.18.(本题满分12分) 如图,ABC ∆的外接圆OCD O ⊥所在的平面,//BE CD,4CD =,2BC =,且1BE =,tan AEB ∠=.(1)求证:平面ADC ⊥平面BCDE .(2)试问线段DE 上是否存在点M ,使得直线AM 与平面ACD 所成角的正弦值为27?若存在,确定点M 的位置,若不存在,请说明理由.19. (本题满分12分)在平面直角坐标系xOy 中,已知向量()cos ,sin e αα=,设,(0)O A e λλ=>,向量ππcos ,sin 22OB ββ⎛⎫⎛⎫⎛⎫=+-⎪ ⎪ ⎪⎝⎭⎝⎭⎝⎭. (1)若π6βα=-,求向量OA 与OB 的夹角; (2)若2AB OB ≥ 对任意实数,αβ都成立,求实数λ的取值范围.20. (本题满分12分)如图,已知四棱锥P ABCD -的底面的菱形,60BCD ︒∠=,点E 是BC 边的中点,AC DE 与交于点O ,PO ABCD ⊥平面(1)求证:PD BC ⊥;(2)若AB PC P AD C ==--的大小; (3)在(2)的条件下,求异面直线PB 与DE 所成角的余弦值。
K12联盟2018届高三年级第一学期期末检测联考数学(理科试题)第Ⅰ卷(共60分)一、选择题:本大题共12个小题,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. 若集合,,则()A. B. C. D.【答案】C【解析】由题意得,,故选C. 点睛:研究一个集合,我们首先要看清楚它的研究对象,是实数还是点的坐标还是其它的一些元素,这是很关键的一步.第二步常常是不等式,求得不等式的解集.在解分式不等式的过程中,要注意分母不能为零.解指数或对数不等式要注意底数对单调性的影响.元素与集合之间是属于和不属于的关系,集合与集合间有包含关系.2. ()A. B. C. D.【答案】C【解析】原式..................... .3. 已知复数(,)满足,则的概率为()A. B. C. D.【答案】B【解析】复数(,),,它的几何意义是以为圆心,1为半径的圆以及内部部分.满足的图象如图中圆内阴影部分所示:则概率故选B.4. 在二项式的展开式中恰好第5项的二项式系数最大,则展开式中含有项的系数是()A. B. C. D.【答案】C【解析】第五项的二项式系数最大,则,通项为,令,故系数是.5. 已知,,若不等式恒成立,则的最大值为()A. 9B. 12C. 18D. 24【答案】B【解析】∵,不等式恒成立∴∵当且仅当a=3b时取等号,∴的最大值为12故选:B点睛:本题主要考查基本不等式,其难点主要在于利用三角形的一边及这条边上的高表示内接正方形的边长.在用基本不等式求最值时,应具备三个条件:一正二定三相等.①一正:关系式中,各项均为正数;②二定:关系式中,含变量的各项的和或积必须有一个为定值;③三相等:含变量的各项均相等,取得最值.6. 函数在上单调递增,则的取值不可能为()A. B. C. D.【答案】D【解析】∵∴令,即∵在上单调递增∴且∴故选D.7. 执行如图所示的程序框图,如果输入的,则输出的()A. B. C. D.【答案】B【解析】若,其前项和为.研究程序框图可知,当时,还要循环一次,,,判断是,退出程序,输出【点睛】本题主要考查算法与程序框图. 程序框图问题的解法:(1)解答程序框图的相关问题,首先要认清程序框图中每个“框”的含义,然后按程序框图运行的箭头一步一步向前“走”,搞清每走一步产生的结论.(2)要特别注意在哪一步结束循环,解答循环结构的程序框图,最好的方法是执行完整每一次循环,防止执行程序不彻底,造成错误.8. 已知一个几何体的正视图、侧视图、俯视图如图所示,则该几何体的体积是()A. 34B. 22C. 12D. 30【答案】B【解析】由该几何体的三视图可知,该几何体是一个三棱锥,如图所示:其中,正方体是棱长为,,,∴∴故选B.9. 已知双曲线:(,)的焦点为,,抛物线:的准线与交于、两点,且与抛物线焦点的连线构成等边三角形,则椭圆的离心率为()A. B. C. D.【答案】D【解析】抛物线为,其焦点为,准线为,代入方程解得.由于与构成等边三角形,则,即,分子分母同时除以得,解得.由于,故椭圆焦点在轴上,且离心率为.10. 本周日有5所不同的高校来我校作招生宣传,学校要求每位同学可以从中任选1所或2所去咨询了解,甲、乙、丙三位同学的选择没有一所是相同的,则不同的选法共有()A. 330种 B. 420种 C. 510种 D. 600种【答案】A【解析】种类有(1)甲,乙,丙,方法数有;(2)甲,乙,丙;或甲,乙,丙;或甲,乙,丙——方法数有;(3)甲,乙,丙;或甲,乙,丙;或甲,乙,丙——方法数有.故总的方法数有种.【点睛】解答排列、组合问题的角度:解答排列、组合应用题要从“分析”、“分辨”、“分类”、“分步”的角度入手.(1)“分析”就是找出题目的条件、结论,哪些是“元素”,哪些是“位置”;(2)“分辨”就是辨别是排列还是组合,对某些元素的位置有、无限制等;(3)“分类”就是将较复杂的应用题中的元素分成互相排斥的几类,然后逐类解决;(4)“分步”就是把问题化成几个互相联系的步骤,而每一步都是简单的排列、组合问题,然后逐步解决.11. 圆:,点为直线上的一个动点,过点向圆作切线,切点分别为、,则直线过定点()A. B. C. D.【答案】B【解析】不妨设,画出图象如下图所示,根据直角三角形射影定理可知,即直线方程为,四个选项中,只有选项符合,故选.12. 已知函数若存在,,且,使,则实数的取值范围为()A. B. C. 或 D. 或【答案】C【解析】当时,,,故符合题意,排除选项,当时,画出图象如下图所示,由图可知此时符合题意,排除选项,故选.第Ⅱ卷(共90分)二、填空题(每题5分,满分20分,将答案填在答题纸上)13. 在中,内角、、所对的边分别是、、,若,则的大小为__________.【答案】【解析】∵∴根据正弦定理可得∵∴,即∵∴故答案为.14. 已知向量,向量在向量方向上的投影为,且,则__________.【答案】【解析】设向量与间的夹角为.∵∴∵∴∵向量在向量方向上的投影为∴,即∴∴故答案为.15. 如图1,在矩形中,,,是的中点;如图2,将沿折起,使折后平面平面,则异面直线和所成角的余弦值为__________.【答案】【解析】取的中点为,连接,,延长到使,连接,,,则∥,所以为异面直线和所成角或它的补角.∵∴,且在中,根据余弦定理得.∴同理可得,又∵平面平面,平面平面,平面∴平面∵平面∴∴,即同理可得,又∵∴在中,∵两直线的夹角的取值范围为∴异面直线和所成角的余弦值为故答案为.点睛:对于异面直线所成的角,一般是通过平移的方法形成异面直线所成的角(或其补角),再根据其所在三角形的边角关系,计算其大小,要注意异面直线所成的角是锐角或直角,若计算出是钝角时,其补角才是异面直线所成的角.16. 若函数,若对任意不同的实数、、,不等式恒成立,则实数的取值范围为__________.【答案】【解析】要使对任意的,成立,也即是最小值的两倍要大于它的最大值.,当,即时,,由基本不等式得,根据上面的分析,则有,解得,即;当,即时,,有基本不等式得,根据上面的分析,则有,解得,即.综上所述.【点睛】本题主要考查函数的最大值和最小值,考查对于新概念或定义的理解.解题的突破口在于“对任意不同的实数、、,不等式恒成立”既然是恒成立,也就是左边相加要比右面的最大值还要大,合起来就是要最小值的两倍,比最大值还要大.根据这个分析利用分类讨论,结合基本不等式来求.三、解答题(本大题共6小题,共70分.解答应写出文字说明、证明过程或演算步骤.)17. 已知数列满足,且.(1)求证:数列是等差数列,并求出数列的通项公式;(2)令,,求数列的前项和.【答案】(1)(2)【解析】试题分析:(1)利用分离常数法,将已知化简得,由此求得的通项公式,进而求得的通项公式.(2)由(1)化简利用分组求和法求得的值.试题解析:(1),且,∴,即,∴,数列是等差数列,∴,∴,∴.(2)由(1)知,∴,∴,.18. 在如图所示的几何体中,,,平面,在平行四边形中,,,.(1)求证:平面;(2)求二面角的余弦值.【答案】(1)见解析(2)【解析】【试题分析】(1)连接交于,取中点,连接,,利用中位线证明,四边形为平行四边形,从而,由此证得平面.(2)以为原点,,,的方向为轴,轴,轴的正方向建立空间直角坐标系,通过计算平面和平面的法向量来求二面角的余弦值.【试题解析】(1)证明:连接交于,取中点,连接,,因为,,又,所以,,从而,平面,平面,所以平面.(2)在平行四边形中,由于,,,则,又平面,则以为原点,,,的方向为轴,轴,轴的正方向建立空间直角坐标系,则,,,,,则,,,设平面的一个法向量为,则由令,得,,所以,,设平面的一个法向量为,则由即令,得,,所以,,所以,所以所求二面角的余弦值为.19. 某市县乡教师流失现象非常严重,为了县乡孩子们能接受良好教育,某市今年要为两所县乡中学招聘储备未来三年的教师,现在每招聘一名教师需要1万元,若三年后教师严重短缺时再招聘,由于各种因素,则每招聘一名教师需要3万元,已知现在该市县乡中学无多余教师,为决策应招聘多少县乡教师搜集并整理了该市50所县乡中学在过去三年内的教师流失数,得到如表的频率分布表:以这50所县乡中学流失教师数的频率代替一所县乡中学流失教师数发生的概率,记表示两所县乡中学在过去三年共流失的教师数,表示今年为两所县乡中学招聘的教师数.为保障县乡孩子教育不受影响,若未来三年内教师有短缺,则第四年马上招聘.(1)求的分布列;(2)若要求,确定的最小值;(3)以未来四年内招聘教师所需费用的期望值为决策依据,在与之中选其一,应选用哪个?【答案】(1)见解析(2)15(3)【解析】【试题分析】(1)先由频率及计算出概率,两所学校流失教师数可能取值为,利用相互独立事件的概率计算公式计算出分布列.(2)由(1)易求得的最小值为15.(3)分别计算出时,招聘教师所需费用的期望值,通过对比期望值确定选较为合适.【试题解析】解:(1)由频数分布表中教师流失频率代替教师流失概率可得,一所县乡中学在三年内流失的教师数为6,7,8,9的概率分别为0.2,0.3,0.3,0.2.所有可能的取值为:12,13,14,15,16,17,18,且,,,,,,,所以的分布列为:(2)由(1)知,,故的最小值为15.(3)记表示两所县乡中学未来四年内在招聘教师上所需的费用(单位:万元).当时,的分布列为:;当时,的分布列为:.可知当时所需费用的期望值小于时所需费用的期望值,故应选.20. 已知直线:与圆相交的弦长等于椭圆:()的焦距长.(1)求椭圆的方程;(2)已知为原点,椭圆与抛物线()交于、两点,点为椭圆上一动点,若直线、与轴分别交于、两点,求证:为定值.【答案】(1)(2)见解析【解析】【试题分析】(1)利用圆心到直线的距离计算出直线与圆相交的弦长,得到.利用求得,得到椭圆方程.(2)设出三个点的坐标,利用点斜式写出直线的方程,令求得两点的坐标,代入并利用两点在椭圆上进行化简.【试题解析】解:(1)由题意知,圆心到直线的距离为,圆的半径为,直线与圆相交的弦长为,则,,又∵,∴,∴椭圆的方程.(2)证明:由条件可知,,两点关于轴对称,设,,则,由题可知,,,所以,.又直线的方程为,令得点的横坐标,同理可得点的横坐标,所以,即为定值.【点睛】本小题主要考查点到直线的距离公式,直线和圆相交所得弦长求法,考查点斜式方程和点与圆锥曲线的位置关系.由于题目涉及直线和圆相交所得弦长,故先利用点到直线距离公式,利用直角三角形求得弦长即.由于两点是由直线交轴而得,故利用点斜式写出直线方程,然后令求出坐标.21. 已知函数有两个零点.(1)求实数的取值范围;(2)设,()是的两个零点,证明:.【答案】(1)(2)见解析【解析】【试题分析】(1)先对函数求导,然后对分成两类,结合函数两个零点,研究函数的单调区间,由此求得的取值范围.(2)将要证明的不等式,利用函数,等价转化为证明,构造函数令,利用导数求得由此证得不等式成立.【试题解析】解:(1)∵,.(2)当时,在上恒成立,∴在上单调递增,显然不符合题意.(3)当时,由,得,当→,→时都有→,当,即时有两个零点.(2)要证,即证,由已知,,即证,即证,即证,即证,又∵,且在单调递增,故只需证,即证,令且,∵,∴在单调递减,∴,∴在上恒成立,∴,故原命题得证.【点睛】本小题主要考查利用导数求单调区间讨论函数的零点问题,考查利用导数证明不等式的问题.导数的主要作用在于利用导数研究函数的图象与性质,主要是单调性,求导后,导函数一般为二次函数、一次函数,或者类似一次、二次函数的形式.如本题中,就是一种类似一次函数的导函数.22. 选修4-4:坐标系与参数方程在直角坐标系中,直线的参数方程为(为参数),以坐标原点为极点,轴的正半轴为极轴建立极坐标系,并使得它与直角坐标系有相同的长度单位,曲线的极坐标方程为.(1)求直线的普通方程和曲线的直角坐标方程;(2)设曲线与直线交于、两点,且点的坐标为,求的值.【答案】(1),(2)9【解析】试题分析:(1)对直线的参数方程消参即可得直线的普通方程,根据即可得曲线的直角坐标方程;(2)将直线方程转化为标准形式的参数方程代入到曲线的直角坐标方程,结合韦达定理即可求出的值.试题解析:(1):,:,即,所以的普通方程是.(2)将直线方程转化为标准形式的参数方程:(为参数),代入中得:,.设,对应的参数分别为,,则,则.23. 选修4-5:不等式选讲已知函数.(1)求函数的最大值;(2)若,都有恒成立,求实数的取值范围.【答案】(1)3(2)【解析】试题分析:(1)由绝对值不等式的性质可得的最大值;(2),恒成立,等价于,即,对进行分类讨论,去绝对值,即可解得实数的取值范围.试题解析:(1),所以的最大值是3.(2),恒成立,等价于,即.当时,等价于,解得;当时,等价于,化简得,无解;当时,等价于,解得.综上,实数的取值范围为.点睛:本题考查绝对值不等式的解法,绝对值三角不等式的应用,考查基本不等式的应用.其中灵活应用分类讨论的思想是解题的关键.2018年高考考前猜题卷理科数学 第Ⅰ卷(共60分)一、选择题:本大题共12个小题,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.设复数z 满足iii z 2|2|++=,则=||z ( ) A .3 B .10 C .9 D .102.已知全集R U =,集合}012|{2≥--=x x x M ,}1|{x y x N -==,则=N M C U )(( )A .}1|{≤x xB .}121|{≤<-x xC .}121|{<<-x x D .}211|{<<-x x3.已知蚂蚁在边长为4的正三角形区域内随机爬行,则它在离三个顶点的距离都大于2的区域内的概率P 为( ) A .631π-B .43C .63π D .414.已知双曲线)0,0(12222>>=-b a by a x ,过双曲线左焦点1F 且斜率为1的直线与其右支交于点M ,且以1MF 为直径的圆过右焦点2F ,则双曲线的离心率是( ) A .12+ B .2 C .3 D .13+5.一个算法的程序框图如图所示,如果输出y 的值是1,那么输入x 的值是( )A .2-或2B .2-或2C .2-或2D .2-或2 6.已知函数)2||,0)(3sin()(πϕωπω<>+=x x f 的图象中相邻两条对称轴之间的距离为2π,将函数)(x f y =的图象向左平移3π个单位后,得到的图象关于y 轴对称,那么)(x f y =的图象( ) A .关于点)0,12(π对称 B .关于点)0,12(π-对称C .关于直线12π=x 对称 D .关于直线12π-=x 对称7.如下图,网格纸上小正方形的边长为1,图中实线画的是某几何体的三视图,则该几何体最长的棱的长度为( )A.32 B.43C. 2D. 411 8.已知等差数列}{n a 的第6项是6)2(xx -展开式中的常数项,则=+102a a ( )A .160B .160-C .350D .320- 9.已知函数)0(212)(<-=x x f x与)(log )(2a x x g +=的图象上存在关于y 轴对称的点,则a 的取值范围是( )A .)2,(--∞B .)2,(-∞C .)22,(--∞D .)22,22(- 10.已知正四棱台1111D C B A ABCD -的上、下底面边长分别为22,2,高为2,则其外接球的表面积为( )A .π16B .π20C .π65D .π465 11.平行四边形ABCD 中,2,3==AD AB ,0120=∠BAD ,P 是平行四边形ABCD 内一点,且1=AP ,若y x +=,则y x 23+的最大值为( ) A .1 B .2 C .3 D .412.设n n n C B A ∆的三边长分别为n n n c b a ,,,n n n C B A ∆的面积为,3,2,1,=n S n …,若n n a a a c b ==++1111,2,2,211nn n n n n a b c a c b +=+=++,则( ) A .}{n S 为递减数列 B .}{n S 为递增数列C .}{12-n S 为递增数列,}{2n S 为递减数列D .}{12-n S 为递减数列,}{2n S 为递增数列二、填空题(每题4分,满分20分,将答案填在答题纸上)13.函数x a x a x x f )3()1()(24-+--=的导函数)('x f 是奇函数,则实数=a .14.已知y x ,满足约束条件⎪⎩⎪⎨⎧≥+≤-≥+-002043y x x y x (R y x ∈,),则22y x +的最大值为 .15.已知F 为抛物线x y C 4:2=的焦点,过点F 作两条互相垂直的直线21,l l ,直线1l 与C 交于B A ,两点,直线2l 与C 交于E D ,两点,则||||DE AB +的最小值为 . 16.在锐角三角形ABC 中,角C B A ,,的对边分别为c b a ,,,且满足ac a b =-22,则BA tan 1tan 1-的取值范围为 . 三、解答题 (本大题共6题,共70分.解答应写出文字说明、证明过程或演算步骤.) 17.已知等比数列}{n a 的前n 项和为n S ,且满足)(221R m m S n n ∈+=+. (1)求数列}{n a 的通项公式; (2)若数列}{n b 满足)(log )12(112+⋅+=n n n a a n b ,求数列}{n b 的前n 项和n T .18.小张举办了一次抽奖活动.顾客花费3元钱可获得一次抽奖机会.每次抽奖时,顾客从装有1个黑球,3个红球和6个白球(除颜色外其他都相同)的不透明的袋子中依次不放回地摸出3个球,根据摸出的球的颜色情况进行兑奖.顾客中一等奖,二等奖,三等奖,四等奖时分别可领取的奖金为a 元,10元,5元,1元.若经营者小张将顾客摸出的3个球的颜色分成以下五种情况:1:A 个黑球2个红球;3:B 个红球;:c 恰有1个白球;:D 恰有2个白球;3:E 个白球,且小张计划将五种情况按发生的机会从小到大的顺序分别对应中一等奖,中二等奖,中三等奖,中四等奖,不中奖.(1)通过计算写出中一至四等奖分别对应的情况(写出字母即可); (2)已知顾客摸出的第一个球是红球,求他获得二等奖的概率;(3)设顾客抽一次奖小张获利X 元,求变量X 的分布列;若小张不打算在活动中亏本,求a 的最大值.19.如图,三棱柱111C B A ABC -中,侧面C C BB 11为菱形,0160=∠CBB ,1AC AB =.(1)证明:平面⊥C AB 1平面C C BB 11;(2)若C B AB 1⊥,直线AB 与平面C C BB 11所成的角为030,求直线1AB 与平面C B A 11所成角的正弦值.20.如图,圆),(),0,2(),0,2(,4:0022y x D B A y x O -=+为圆O 上任意一点,过D 作圆O 的切线,分别交直线2=x 和2-=x 于F E ,两点,连接BE AF ,,相交于点G ,若点G 的轨迹为曲线C .(1)记直线)0(:≠+=m m x y l 与曲线C 有两个不同的交点Q P ,,与直线2=x 交于点S ,与直线1-=y 交于点T ,求OPQ ∆的面积与OST ∆的面积的比值λ的最大值及取得最大值时m 的值.(注:222r y x =+在点),(00y x D 处的切线方程为200r yy xx =+)21.已知函数x a x g x x f ln )(,21)(2==. (1)若曲线)()(x g x f y -=在2=x 处的切线与直线073=-+y x 垂直,求实数a 的值;(2)设)()()(x g x f x h +=,若对任意两个不等的正数21,x x ,2)()(2121>--x x x h x h 恒成立,求实数a 的取值范围;(3)若在],1[e 上存在一点0x ,使得)(')()('1)('0000x g x g x f x f -<+成立,求实数a 的取值范围.请考生在22、23二题中任选一题作答,如果都做,则按所做的第一题记分. 22.选修4-4:坐标系与参数方程在直角坐标系xOy 中,曲线1C 的参数方程为⎪⎩⎪⎨⎧==21t a y t x (其中t 为参数,0>a ),以坐标原点O 为极点,x 轴的正半轴为极轴建立的极坐标系中,直线l :0sin cos =+-b θρθρ与2C :θρcos 4-=相交于B A ,两点,且090=∠AOB . (1)求b 的值;(2)直线l 与曲线1C 相交于N M ,两点,证明:||||22N C M C ⋅(2C 为圆心)为定值. 23.选修4-5:不等式选讲已知函数|1||42|)(++-=x x x f . (1)解不等式9)(≤x f ;(2)若不等式a x x f +<2)(的解集为A ,}03|{2<-=x x x B ,且满足A B ⊆,求实数a的取值范围.参考答案一、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,只有一项是符合题目要求的.二、填空题:本大题共4小题,每小题5分,共20分. 13.3 14.8 15.16 16.)332,1( 三、解答题:本大题共6小题,满分70分.解答须写出文字说明、证明过程和演算步骤.17.解:(1)由)(221R m m S n n ∈+=+得⎪⎪⎪⎩⎪⎪⎪⎨⎧+=+=+=282422321m S m S m S ,)(R m ∈,从而有4,2233122=-==-=S S a S S a , 所以等比数列}{n a 的公比223==a a q ,首项11=a ,因此数列}{n a 的通项公式为)(2*1N n a n n ∈=-.(2)由(1)可得12)22(log )(log 1212-=⋅=⋅-+n a a n n n n , ∴)121121(21)12)(12(1+--⨯=-+=n n n n b n ∴)1211215131311(2121+--++-+-⨯=+++=n n b b b T n n 12+=n n. 18.解:(1)4011203)(31023===C C A P ;12011)(310==C B P ,10312036)(3102416===C C C C P ,2112060)(3101426===C C C D P ,6112020)(31036===C C E P∵)()()()()(D P C P E P A P B P <<<<, ∴中一至四等奖分别对应的情况是C E A B ,,,.(2)记事件F 为顾客摸出的第一个球是红球,事件G 为顾客获得二等奖,则181)|(2912==C C F G P .(3)X 的取值为3,2,2,7,3---a ,则分布列为由题意得,若要不亏本,则03212103)2(61)7(401)3(1201≥⨯+⨯+-⨯+-⨯+-⨯a , 解得194≤a ,即a 的最大值为194.19.解:(1)证明:连接1BC ,交C B 1于O ,连接AO , ∵侧面C C BB 11为菱形,∴11BC C B ⊥ ∵为1BC 的中点,∴1BC AO ⊥ 又O AO C B = 1,∴⊥1BC 平面C AB 1又⊂1BC 平面C C BB 11,∴平面⊥C AB 1平面C C BB 11.(2)由B BO AB C B BO C B AB =⊥⊥ ,,11,得⊥C B 1平面ABO 又⊂AO 平面ABO ,∴C B AO 1⊥,从而1,,OB OB OA 两两互相垂直,以O 为坐标原点,的方向为x 轴正方向,建立如图所示的空间直角坐标系xyz O -∵直线AB 与平面C C BB 11所成角为030,∴030=∠ABO设1=AO ,则3=BO ,∵0160=∠CBB ,∴1CBB ∆是边长为2的等边三角形∴)0,1,0(),0,1,0(),0,0,3(),1,0,0(1-C B B A ,则)1,0,3(),0,2,0(),1,1,0(1111-==-=-=AB B A C B AB 设),,(z y x =是平面C B A 11的法向量,则⎪⎩⎪⎨⎧=⋅=⋅00111C B n B A n 即⎩⎨⎧=-=-0203y z x ,令1=x ,则)3,0,1(=n设直线1AB 与平面C B A 11所成的角为θ, 则46||||||,cos |sin ==><=n AB θ. 20.解:(1)易知过点),(00y x D 的切线方程为400=+y y x x ,其中42020=+y x ,则)24,2(),2,2(000y x F y x E +--, ∴4116416416424424220020000021-=-=--=-⋅-+=y y y x y x y x k k 设),(y x G ,则144122412221=+⇒-=+⋅-⇒-=y x x y x y k k (0≠y ) 故曲线C 的方程为1422=+y x (0≠y ) (2)联立⎩⎨⎧=++=4422y x mx y 消去y ,得0448522=-++m mx x ,设),(),,(2211y x Q y x P ,则544,5822121-=-=+m x x m x x ,由0)44(206422>--=∆m m 得55<<-m 且2,0±≠≠m m∴22221221255245444)58(24)(11||m m m x x x x PQ -=-⨯--⨯=-++=,易得)1,1(),2,2(---+m T m S , ∴)3(2)3()3(||22m m m ST +=+++=,∴22)3(554||||m m ST PQ S S OSTOPQ +-===∆∆λ,令)53,53(,3+-∈=+t t m 且5,3,1≠t ,则45)431(4544654222+--⨯=-+-=t t t t λ, 当431=t ,即43=t 时,λ取得最大值552,此时35-=m . 21.解:(1)xax y x a x x g x f y -=-=-=',ln 21)()(2 由题意得322=-a,解得2-=a (2))()()(x g x f x h +=x a x ln 212+=对任意两个不等的正数21,x x ,2)()(2121>--x x x h x h 恒成立,令21x x >,则)(2)()(2121x x x h x h ->-,即2211)(2)(x x h x x h ->-恒成立 则问题等价于x x a x x F 2ln 21)(2-+=在),0(+∞上为增函数 2)('-+=xax x F ,则问题转化为0)('≥x F 在),0(+∞上恒成立,即22x x a -≥在),0(+∞上恒成立,所以1)2(max 2=-≥x x a ,即实数a 的取值范围是),1[+∞. (3)不等式)(')()('1)('0000x g x g x f x f -<+等价于0000ln 1x ax a x x -<+,整理得01ln 000<++-x ax a x ,构造函数x a x a x x m ++-=1ln )(, 由题意知,在],1[e 上存在一点0x ,使得0)(0<x m2222)1)(1()1(11)('x x a x x a ax x x a x a x m +--=+--=+--=因为0>x ,所以01>+x ,令0)('=x m ,得a x +=1①当11≤+a ,即0≤a 时,)(x m 在],1[e 上单调递增,只需02)1(<+=a m ,解得2-<a ; ②当e a ≤+<11,即10-≤<e a 时,)(x m 在a x +=1处取得最小值.令01)1ln(1)1(<++-+=+a a a a m ,即)1l n (11+<++a a a ,可得)1ln(11+<++a aa (*) 令1+=a t ,则e t ≤<1,不等式(*)可化为t t t ln 11<-+ 因为e t ≤<1,所以不等式左端大于1,右端小于或等于1,所以不等式不能成立. ③当e a >+1,即1->e a 时,)(x m 在],1[e 上单调递减,只需01)(<++-=eaa e e m 解得112-+>e e a .综上所述,实数a 的取值范围是),11()2,(2+∞-+--∞e e . 22.解:(1)由题意可得直线l 和圆2C 的直角坐标方程分别为0=+-b y x ,4)2(22=++y x∵090=∠AOB ,∴直线l 过圆2C 的圆心)0,2(2-C ,∴2=b . (2)证明:曲线1C 的普通方程为)0(2>=a ay x ,直线l 的参数方程为⎪⎪⎩⎪⎪⎨⎧=+-=ty t x 22222(t 为参数),代入曲线1C 的方程得04)2222(212=++-t a t , 04212>+=∆a a 恒成立,设N M ,两点对应的参数分别为21,t t ,则821=t t , ∴8||||22=N C M C , ∴||||22N C M C 为定值8.23.解:(1)由9)(≤x f 可得9|1||42|≤++-x x ,即⎩⎨⎧≤->9332x x 或⎩⎨⎧≤-≤≤-9521x x 或⎩⎨⎧≤+--<9331x x解得42≤<x 或21≤≤-x 或12-<≤-x , 故不等式9)(≤x f 的解集为]4,2[-.(2)易知)3,0(=B ,由题意可得a x x x +<++-2|1||42|在)3,0(上恒成立⇒1|42|-+<-a x x 在)3,0(上恒成立1421-+<-<+-⇒a x x a x 在)3,0(上恒成立 3->⇒x a 且53+->x a 在)3,0(上恒成立⎩⎨⎧≥≥⇒50a a 5≥⇒a .。
第一部分听力(共两节,满分30分)做题时,先将答案标在试卷上。
录音内容结束后,你将有两分钟的时间将试卷上的答案转写到答题卡上。
第一节(共5小题;每小题1.5分,满分7.5分)听下面5段对话。
每段对话后有一个小题,从题中所给的A、B、C三个选项中选出最佳选项,并标在试卷的相应位置。
听完每段对话后,你都有10秒钟的时间来回答有关小题和阅读下一小题。
每段对话仅读一遍。
1. Where does the conversation probably take place?A. In a bookstore.B. In a library.C. Ina classroom.2. What are the speakers doing?A. Doing shopping.B. Designing clothes.C. Getting dressed.3. What does the man mean?A. He’ll move the boxes for the woman.B. He wants Bob to give him a hand.C. He can’t help the woman.4. What does the man think of the seals in Prestige Air’s planes?A. Small.B. Wide.C. Comfortable.5. What are the speakers mainly talking about?A. The man’s early projects.B. The woman’s term paper.C. The way to write a paper.第二节(共15小题;每小题1.5分,满分22.5分)听下面5段对话或独白,每段对话或独白后有几个小题,从题中所给的A、B、C三个选项中选出最佳选项,并标在试卷的相应位听每段对话或独白前,你将有时间阅读各个小题,每小题5秒钟;听完后,各小题将给出5秒钟的作答时间。
每段对话或独白读两遍。
听第6段材料,回答第6、7题。
6. Where are the speakers?A. At the woman’s home.B. At school.C. At a hospital.7. What causes the woman’s headaches?A. Her terrible school marks.B. The bad condition of her eyes.C. Her unpleasant relationship with her teachers.听第7段材枓,回答第8、9题。
8. Why didn’t the woman major in art?A. It needed a lot of money.B. It was unpractical.C. It required hard work.9. How does the man feel about the woman’s decision?A. Pitiful.B. Envious.C. Doubtful. 听第8段材料,回答第10至12题。
10. Who is calling?A. Mrs. Bell.B. Mary Smith.C. Jacob Waters.11. What day is it today?A. July 3rd.B. July 5th.C. July 8th.12. What is the message about?A. A meeting.B. Sick leave.C. A visit to the Culture Centre听第9段材料,回答第13至16题。
13. What will the woman do for her vacation?A. Take a trip to Brazil.B. Join a sum.er camp.C. Visit son, friends.14. Why did the man change his travel plans?A. To teach some kids to swim.B. To learn to drive.C. To save up for a car.15. How will the man go to London?A. By car.B. By plane.C. By train.16. What might be the relationship between the two speakers?A. Relatives.B. Classmates.C. Teacher and student.听第10段材料,回答第17至20题。
17. Why did the man choose that part of Africa to visit?A. It is good for walking.B. He had been there before.C. It will soon change.18. What made the team’s journey slow?A. Carrying heavy equipment.B. Finding somewhere safe to camp.C. Clearing paths through the forest.19. What did the man worry about during the trip?A. The safety of the team.B. Losing his notebook.C. Dangerous animals.20. Why was the team short of food?A. The trip took longer than expected.B. Some of the food went bad too quickly.C. Some people ate more than they should.第二部分阅读理解(共两节,满分40分)(注:山西考生,满分60分)第一节(共15小题;每小题2分,满分30分)(注:山西考生,每小题3分,满分45分)阅读下列短文,从所给的四个选项(A、B、C、D)中选出最佳选项,并在答题卡上将选项涂黑。
AAs fun and enriching as traveling can be, it can also prove to be very expensive.That’s why we’ve rounded up a list of the best international destinations to go to in 2018 that won’t break the bank.LaosLocated in Southeast Asia, Laos is an underrated country with a ton to offer, ill ere is an abundance of French colonial architecture, stunning Buddhist monasteries (修道院), jungles, and the nicest locals. The best part is it’s not super touristy, so you won’t be subject to jacked up prices or overwhelming crowds.For local meals and street eats, you can expect to pay $2 to $4, while a gourmet (精美的) meal with drinks will cost you $ 15 to $ 50. You can even get a boutique hotel or resort for us low as $ 50.PortugalPortugal is certainly having a moment right now, with tourists flocking to the Southern European country that borders Spain. Here you’ll find major cities filled with culture, stunning beaches, picturesque landscapes, sensational cuisine, and port wine.You can get a basic hotel starting from about $ 35, or a boutique hotel starting from about $ 120. As far as food, you can get a lunch special al a family-run restaurant for $ 8 to $ 12, and dinner for two in a top restaurant for $ 92.NicaraguaAnother country where tourism has yet to boom, this Central American country is set between the Pacific Ocean and the Caribbean Sea and is best known for its lakes, volcanoes, and beach es. Because Nicaragua isn’t quite on everyone’s radar just yet, you can expect low prices. Go during the rainy season, and you can expect even a 20% discount.A typical meal will cost you $4, a gourmet meal $20, and a double bed in a luxury hotel will cost you between $ 80 to $ 120.21. Where could you go to enjoy tropical jungles?A. LaosB. PortugalC. SpainD. Nicaragua22. Visiting Nicaragua in the rainy season, for a gourmet meal you will pay ?A. $ 4.B. $8.C. $ 16.D. $20.23. What do these destinations have in common according to the text?A. They are European countries.B. Tourists can spend less money.C. They are underdeveloped countries.D. Tourists can enjoy living by the sea.BWhatever Rock was doing down there, it made enough noise for me to go to him. By the time I made it to the bottom of the stairs, he was running up, and he never came up the stair, no matter what. I think that was his way of telling me, “We’ve got to go back up.”When I got to the top of the stairs, I turned around and saw a light on, but I didn’t remember leaving one on. I walked downstairs again, and that’s when I saw fire. I immediately should to my wife to wake up and get our three kids. I grabbed a knife and cut out the plastic that covered the window to the porch roof. I then broke the window and kicked out the screen. I got everybody out on the roof and threw a blanket out there so we wouldn’t slip off. It was cold, January cold. Then I started screaming for help. But help never came.Now, I’m scared of heights and have physical issues, what with my rheumatoid arthritis (类风湿性关节炎), but I couldn’t let ray family bum up. So I jumped off the roof. I didn’t run to the edge, I just jumped and got the wind knocked out of me when I landed.I found our ladder, placed it against the house, and climbed back up to the roof.I wrapped my arms around my daughter and canned my nine-month-old with my teeth, by his little sleeper. Then I climbed down the ladder. Once on ground, I had my little girl hold her brother, and I went back up to the roof lo get my other daughter. Then I went back up again and got my wife. I tried to get my dog, but he just disappeared in the black smoke. I never saw him alive again.I’m no hero. I’m just an ordinary person who’d help anybody. This happenedto be the time when I helped my own family. I live to protect my family. Just like Rock — he lived lo protect us.24. Why did Rock make enough noise?A. Rock caused the fire and tried to escape.B. Rock was warming up itself to fight cold.C. Rock was playing upstairs and downstairs.D. Rock tried to remind the author of the fire.25. The author jumped off the roof .A. to call for helpB. to challenge himselfC. to find tools for rescueD. to escape being burned26. What can we learn about the author?A. Strict and devoted.B. Smart and sociable.C. Responsible and brave.D. Powerful and considerate.27. Which of the following can be the best title of the text?A. Rock’s Heroic LifeB. Escape from the FireC. A Lesson I Have LearntD. My Adventure ExperienceCIf you’re a commuter (通勤者) or drive on the highway often, you’ve probably seen those tall wall-like structures alongside the road. You may think they’re there to prevent cars and trucks from going off the road, or to provide privacy nearby neighborhoods. B ut that’s actually not their main purpose.It all started back when the 1958 Hollywood Bowl was drowned out by nearby highway noise. Ever since, tall barriers made out of noise-cancelling materials were construct along the busiest areas of America’s highw ays to prevent the noise from affecting surrounding areas. There are now 2,748 miles of these walls across the U.S.According to the Federal Highway Administration, barrier walls can reduce highway noise by almost half. The structures are typically made out of wood, concrete or brick-materials that absorb or reduce sound.The critical aspect of the construction of these walls is their height. They’re built high enough to be over the line of sight, usually much taller than any car ortruck. Building them up this high reduces sound waves by about 5-10 decibels. Human ears can’t usually notice a difference below 3 decibels, so the taller the better!The barriers are most effective when they are built within 61 meters of the road, which is why they can seem like safety barriers. They also cannot have any openings, or else the noise will leak through and the wall will be ineffective.The FWHA also puts aesthetic standards on the noise reducing walls. They “must be designed to be visually appealing and must be designed to preserve aesthetic values and scenic views,” according to the organization’s website. This is done to keep the natural landscape that typically surrounds highways complete and make them pleasant for surrounding residential communities as well.28. What’s the main purpose of tall walls according to the text?A. To keep wildlife away from the road.B. To prevent cars from going off the road.C. To provide privacy to nearby neighborhoods.D. To prevent the noise from disturbing surroundings.29. What is the vital aspect of tall walls according to the text?A. the heightB. the materialC. the placeD. the style30. What can we learn about safety barriers according to the text?A. They were built since 1958.B. They are made from wood, or concrete.C. They stand within 61 meters of the road.D. They are built at a similar height of tall walls.31. What does the underlined word “aesthetic” in Para. 6 mean?A. noisy B artistic C. typicalD. naturalDHomeless people face a lot of challenges. Some of the most basic challenges, however, spring from not having regular access to clean water and cleaning stuff such as soap and shampoo. And poor personal hygiene (卫生) can he particularly troublingfor homeless teens.That challenge inspired a young researcher, Leia Glunckman, to invent a multi-purpose product. It would need to absorb sweat and oil from skin and hair. It would need to clean teeth. Plus, it would need to kill bacteria without being harmful to people. She wanted her ingredients to be natural and biodegradable (可降解的).Leia started by going to stores and looking at I he ingredient (原料) lists for tooth powders, body powders and dry shampoos. Then she put together eight different trial recipes of her own. She tested each mixture to see how well it absorbed body oil and cleaned hair, to find out how these might work as a toothpaste, she tested them al removing coffee stains from eggshells.Eventually, Leia settled on three working recipes. Each contains salt and baking powder. The salt helps clean teeth and remove dirt, she notes. Baking powder helps absorb smells. Her three recipes’ other ingredients differ. Some of those ingredients included cloves, cinnamon and chamomile. Those sorts of things give her products different tastes and smells. That would let teens choose a product based on personal preferences.Leia wants to develop her products further. “Could it be used to drive off mosquitoes?” she asks.“Or does it attract them? These are questions I want to answer next,” she notes.Science offers a way to go about “solving problems and helping people,” says Leia. And she thinks her products could benefit a broad range of people, not just the homeless. Anyone in an area with little or no access to clean water could find her products useful, she says.32. What made Leia make the product according to the text?A. Her personal experience.B. The suffering of homeless people.C. Poor personal hygiene for homeless people.D. Her curiosity about invention and helping others.33. The third paragraph mainly tells us .A. How Leia made the productB. how effective the product isC. what functions the product hasD. what ingredients the product has34. What can we learn about the product from the fourth paragraph?A. People can buy it in the market now.B. The product only has three varieties.C. Salt is used lo clear smells and remove dirt.D. It can be custom-made to suit personal taste.35. How does Leia feel about her invention?A. It has some faults.B. It is quite satisfactory.C. It still needs improving.D. It is useful in remote area.第二节(共5小题;每小题2分,满分10分)(注:山西考生,每小题3分,满分15分)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。