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2024-2025 学年高二第二学期六校联合体期末考试
高二数学
一、选择题:本大题共 8 小题,每小题5 分,共40 分.在每小题给出的四个选项中,只有一
项是符合题目要求的,请把答案填涂在答题卡相应位置上.
1.设集合M={1,0,2a},N={1,a2},且N M,则实数a的值是 ( )
A. -2 B. 0 C. 1 D. 2
⊆
2.设x∈R,则“cosx=1”是“sinx=0”的 ( )
A.充分不必要条件 B.必要不充分条件
C.充分必要条件 D.既不充分也不必要条件
3.已知x>0,y>0,且4x+y-xy=0,则x+y的最小值为 ( )
A.8 B. 9 C.10 D. 11
x·cosx
4.函数f(x)= 的图象大致为 ( )
e
|x|
A. B. C. D.
5.行列式是近代数学中研究线性方程的有力工具,最简单的二阶行列式的运算定义如下:
|a b|=ad
c d
|2a 3 a 3 -a 2|
-bc,已知S 是等比数列{a }的前n项和,若 =0,a =1,q≠1,则S = ( )
n n a a -a 1 7
4 3 2
A.31 B.63 C.127 D.255
6.抛物线C的顶点为坐标原点,焦点在x轴上,直线 x=3交C于M,N两点,C的准线交x轴于点P,
若PM⊥PN,则C的方程为 ( )
A.y2=4x B.y2=6x C.y2=8x D.y2=12x
7.将各位数字之和为6的三位数叫“幸运数”,比如123,402,则所有“幸运数”的个数为 ( )
A.19 B.20 C.21 D.22
8.已知函数f(x)及其导函数f'(x)的定义域均为R,记g(x)=f'(x),已知f(2x+1)和g(x+2)都是偶函数,且
2025
g(2)=1,则 ∑ g(k)的值为 ( )
k=0
A.1 B.-1 C.2025 D.-2025二、选择题:本大题共 3 小题,每小题6 分,共18 分.在每小题给出的四个选项中,有多项
符合题目要求,请把答案填涂在答题卡相应位置上.全部选对得 6分,部分选对得部分分,
不选或有错选的得 0分.
π π
9.已知函数f(x)=3sin(ωx- ),其中ω>0,且函数的两个相邻对称轴之间的距离为 ,则下列说法正确的是
6 2
( )
A.ω=2
π
B.函数图象关于点( ,0)对称
24
π
C.函数在区间[0, ]单调递增
6
π
D.函数的图象可以由y=3sinωx的图象向右平移 个单位得到
6
10.下列等式正确的是 ( )
10 10
A.∑Ck =210 B.∑C2=C3
10 k 11
k=1 k=2
10 10 k 1
C.∑(-1)kCk =0 D.∑ =1-
10
k=1 k=1(k+1)! 11!
x2 y2
11.已知双曲线C: - =1(a>0,b>0)的左、右焦点分别为F 、F ,过F 作斜率为
1 2 2
a2 b2
- 15的直线与双曲线的右支交于A、B两点(A在第一象限),|AB|=|BF |,P为线段AB的中点,O
1
为坐标原点,则下列说法正确的是 ( )
A.|AF |=2|AF | B.双曲线C的离心率为2
1 2
15
C.直线OP的斜率为- D.△AF F 的面积为2 15a2
1 2
5
三、填空题:本大题共 3小题,每小题 5 分,共 15分.请把答案填写在答题卡相应位置上.
12.圆x2+y2=1与圆x2+y2-6x-8y+9=0的公切线的条数是____▲____条.
1 1 — 3 —
13.设A,B是一个随机试验中的两个随机事件,且P(A)= ,P(B)= ,P(A+B)= ,则P(B|A)=___▲_____.
3 2 4
14.已知实数x,y,z均小于1,且满足ex-elog23=e·(x-log
2
3),ey-elog35=e·(y-log
3
5),
ez-elog58=e·(z-log
5
8),其中e为自然对数的底数.则x,y,z的大小关系是___▲____.
(用“<”连接)
四、解答题:本大题共 5 小题,共77分.请在答题卡指定区域内作答,解答时应写出必要的
文字说明,证明过程或演算步骤.15.(本题满分13分)
如图,在直三棱柱ABC-A B C 中,AB=AC=AA =2,∠BAC=90°,E,F分别为C C,BC的中点.
1 1 1 1 1
(1)求证:A B⊥B C;
1 1
(2)求直线A B与平面AEF所成角的余弦值.
1
16.(本题满分15分)
某公司生产一种电子产品,每批产品进入市场之前,需要对其进行检测,现从某批产品中随机抽取10
箱进行检测,其中有6箱为一等品.
(1)现从这10箱产品中随机抽取3箱,求这三箱中恰有两箱是一等品的概率;
(2)用频率估计概率,在这批产品中随机抽取3箱,用X表示抽到一等品的箱数,求X的分布列和数学
期望.
17.(本题满分15分)
x2 y2 3
已知椭圆C: + =1(a>b>0)的离心率为 ,以椭圆的四个顶点为顶点的四边形的面积为4.
a2 b2 2
(1)求椭圆C的标准方程;
(2)记椭圆C的左顶点为A,右顶点为B,过点B作不垂直于坐标轴的直线l交椭圆于另一点G,过点A
→ 2→
作l的垂线,垂足为H,且BG= BH,求直线l的方程.
5
18.(本题满分17分)
已知f(x)=a·ex-x.
(1)求f(x)在x=0处的切线方程;(2)求f(x)的单调区间;
(3)若方程a·ex-x=0有两个不相等的实数根x ,x ,且x <x ,求证:(1-a)·x >a.
1 2 1 2 1
19.(本题满分17分)
已知数列{a }的前n项和为S ,若存在常数λ(λ>0),使得λa ≥S 对任意n∈N*都成立,则称数列{a }
n n n n+1 n
具有性质M(λ).
(1)若数列{a }的通项公式a =-2n+1,求证:数列{a }具有性质M(3);
n n n
(2)设数列{a }的各项均为正数,且{a }具有性质M(λ).
n n
①若数列{a }是公比为q的等比数列,且λ=4,求q的值;
n
②求λ的最小值.2024-2025 学年高二第二学期六校联合体期末考试
高二数学参考答案
一、单选题
1 2 3 4 5 6 7 8
D A B C C D C B
二、多选题
9 10 11
AC BD ABC
三、填空题
12 13 14
1
3 x<y<z
4
四、解答题
15.(1)证明:连接AB ,
1
因为三棱柱ABC-A B C 为直三棱柱,所以AA ⊥平面ABC,
1 1 1 1
又AC平面ABC,所以AC⊥AA ,
1
又AC⊥AB,AB∩AA =A,AB,AA 平面ABA ,所以AC⊥平面ABA ,
1 1 1 1
又A B平面ABA ,则A B⊥AC,···································································2分
1 1 1
因为在直三棱柱ABC-A B C 中,AB=AA ,所以四边形ABB A 为正方形,
1 1 1 1 1 1
所以A B⊥AB ,···························································································4分
1 1
因为AC∩AB =A,AC、AB 平面ACB ,所以A B⊥平面ACB ,·························5分
1 1 1 1 1又B C平面ACB ,则A B⊥B C.··································································6分
1 1 1 1
(2)因为直三棱柱ABC-A B C 中,∠BAC=90°,
1 1 1
所以AB,AC,AA 两两垂直,
1
所以以A为原点,分别以AB,AC,AA 所在的直线为x,y,z轴建立如图所示的空间直角坐标系,
1
则A(0,0,0),A (0,0,2),B(2,0,0),E(0,2,1),F(1,1,0),
1
→
所以A B=(2,0,-2),················································································8分
1
→ →
AE=(0,2,1),AF=(1,1,0).
→
n·AE=2b+c=0
设平面AEF的一个法向量为n=(a,b,c),则
→
,
n·AF=a+b=0
令a=1可得n=(1,-1,2).······································································ 10分
设A B与平面AEF所成角为θ,
1
→
→
|n·A
1
B|
2 3
所以sinθ=|cos<n,A B>|= = = ,······················12分
1 →
|n||A B| 4+4× 1+1+4 6
1
3
即A B与平面AEF成角的正弦值为 ,
1
6
33
所以A B与平面AEF成角的余弦值为 .······················································13分
1
6
16.解:(1)记“这三箱中恰有两箱是一等品”为事件A,·····································1分则P(A)= C2 6 C1 4= 60 = 1 .···············································································4分
C3 120 2
10
6 3
(2)由题意,任取一个,取到一等品的概率为 = ,············································5分
10 5
3
因为X可能的取值为0,1,2,3,且X服从二项分布(3, )
5
2 8
所以P(X=0)=( )3= ,··············································································7分
5 125
3 2 36
P(X=1)=C1 ·( )2= ,···············································································9分
3
5 5 125
3 2 54
P(X=2)=C2
3
( )2 = ,··············································································11分
5 5 125
3 27
P(X=3)=( )3= ,···················································································13分
5 125
3 9
数学期望E(X)=3× = .············································································15分
5 5
1
17.(1)由题意:S= ·2a·2b=4,所以ab=2,····················································1分
2
c 3
又因为 = ,
a 2
所以a=2,b=1,························································································3分
x2
所以椭圆的方程: +y2=1.·········································································4分
4
(2)由题意,设直线l的方程为y=k(x-2),
y=k(x-2)
由 ,可得(1+4k2)x2-16k2x+16k2-4=0,
x2+4y2=4
16k2 8k2-2 -4k
因为2+x = ,所以x = ,代入直线方程可得y = .····················7分
G G G
1+4k2 1+4k2 1+4k2
(注:写出完整坐标或一个坐标分量都得3分)
1
过点B与l垂直的直线方程为y=- (x+2),
k
1
y=- (x+2)
由 k 可得x =
2k2-2
,y =
-4k
,···············································10分
H H
y=k(x-2) k2+1 k2+1(注:写出完整坐标或一个坐标分量都得3分)
→ 2→ 2
因为BG= BH,所以(x -2,y )= (x -2,y )
G G H H
5 5
2
法一:x -2= (x -2),··············································································11分
G H
5
8k2-2 2 2k2-2
所以 -2= ·( -2),解得k=±1,··················································13分
1+4k2 5 k2+1
所以直线l的方程:y=x-2或y=-x+2.····················································· 15分
2
法二:y = y ,·························································································11分
G H
5
-4k 2 4k
所以 = ·(- ),解得k=±1,························································· 13分
1+4k2 5 1+k2
所以直线l的方程:y=x-2或y=-x+2.····················································· 15分
y=k(x-2)
(注:如果先证一个结论:k
AG
·k
BG
=- 1 ,因为k
BG
=k,k
AG
=- 1 ,由 y=- 1 (x+2) 可得G( 8k2-2 , -4k ),
4 4k k 1+4k2 1+4k2
酌情给分)
18.(1)因为f'(x)=a·ex-1,所以f'(0)=a-1,···················································2分
又因为f(0)=a,
所以f(x)在x=0处的切线方程为y-a=(a-1)x,即y=(a-1)x+a.·······················4分
(2)因为f'(x)=a·ex-1,
①若a≤0,则f'(x)<0恒成立,所以f(x)在(-∞,+∞)单调递减,无增区间.········7分
②若a>0,令f'(x)>0得x>-lna,令f'(x)<0得x<-lna,所以f(x)在(-∞,-lna)单调递减,在(-lna,
+∞)单调递增.·························································································10分
(注:没写综上不扣分,a=0单独写不扣分,a=0漏掉扣1分)(3)若a≤0,由(2)知f(x)在(-∞,+∞)单调递减,方程至多有一个实根,不符题意,
所以a>0.······························································································· 11分
x
法1.由题意知a·ex1=x ,所以a= 1,且x >0.
1 ex1 1
x
要证(1-a)x >a,只要证(1-a)·ae x1>a,只要证(1-a)·e x1>1,只要证(1- 1 )·e x1>1,只要证e x1-x >1.
1 ex1 1
··············································································································· 14分
令g(x)=ex-x-1,x>0,g'(x)=ex-1>0,
所以g(x)在(0,+∞)单调增,g(x)>g(0)=0,
因为x >0,所以g(x )>0,即ex1-x >1,
1 1 1
所以(1-a)x >a得证.················································································ 17分
1
法2.由(2)得f(x)在(-∞,-lna)单调递减,在(-lna,+∞)单调递增,
1
所以f(-lna)=1+lna<0,所以0<a< .
e
a a
因为 <1<-lna,所以x , ∈(-∞,-lna),
1
1-a 1-a
a a a
要证(1-a)x >a,只要证x > ,只要证f(x )<f( ),只要证f( )>0.
1 1 1
1-a 1-a 1-a
a a a a 1
而f( )=a·e1-a - =a·(e1-a - ),······················································ 14分
1-a 1-a 1-a
令g(x)=ex-x-1,x>0,g'(x)=ex-1>0,
所以g(x)在(0,+∞)单调增,g(x)>g(0)=0,
a a 1
所以x>0时,ex-x-1>0恒成立,令x= 得e1-a - >0,
1-a 1-a
a
所以f( )>0.
1-a
所以(1-a)x >a得证.················································································ 17分
1
(-1-2n+1)n
19.(1)设由数列{a }的通项公式,a =-2n+1,S = =-n2,············2分
n n n
2
于是3a -S =3(-2n+1)+(n+1)2=(n-2)2≥0,
n n+1即3a ≥S ,
n n+1
所以数列{a }具有性质M(3).·········································································4分
n
(2)①由数列{a }具有性质M(4),得4a ≥S ,又等比数列{a }的公比为q,
n n n+1 n
若q=1,则4a ≥(n+1)a ,解得n≤3,与n为任意正整数相矛盾;·······················5分
1 1
当q≠1时,4a qn-1≥a ·
1-qn+1
,而a >0,整理得4qn-1≥
1-qn+1
,
1 1 n
1-q 1-q
若0<q<1,则qn-1≥ 1 ,解得n<1+log 1 ,与n∈N*矛盾;·················6分
q
(q-2)2 (q-2)2
若q>1,则q n-1 (q-2)2≤1,当q=2时,q n-1 (q-2)2≤1恒成立,满足题意;···········7分
当q>1且q≠2时,q n-1≤ 1 ,解得n<1+log 1 ,与n∈N*矛盾;···········8分
q
(q-2)2 (q-2)2
所以q=2.·································································································9分
②由λa ≥S ,得λa ≥S ,即λ(S -S )≥S ,··········································11分
n n+1 n+1 n+2 n+1 n n+2
因此λS ≥λS +S ≥2 λS S ,即 S n+2≤ λ · S n+1,············································13分
n+1 n n+2 n n+2
S n+1 4 S n
则有 S n+1≤ λ · S n ≤( λ )2· S n-1≤…≤( λ ) n-1 · S 2,····················································· 15分
S n 4 S n-1 4 S n-2 4 S 1
由数列{a }各项均为正数,得S <S ,从而1<( λ )n-1 S 2,即( λ )n-1> S 1,
n n n+1
4 S 4 S
1 2
S
若0<λ<4,则n<1+log 1,与n∈N*矛盾,··················································16分
λ
S
4 2
因此当λ≥4时,( λ ) n-1≥1 n-1> S 1恒成立,符合题意,
4 S
2
所以λ的最小值为4.··················································································· 17分