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中学生标准学术能力诊断性测试 2023 年 9 月测试
数学试卷
本试卷共 150分,考试时间 120分钟。
一、单项选择题:本题共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.
x−1 1
1.设集合A=x ,xR,B= xN1 x5 ,则
x+2 2
第1页 共4页 第2页 共4页
A B =
A. 2 B. 2 , 3 C. 3 , 4 D. 2,3,4
2.欧拉公式ei=cos+isin把自然对数的底数 e 、虚数单位 i 、三角函数联系在一起,充分体现
了数学的和谐美.已知实数指数幂的运算性质同样也适用于复数指数幂,则 i i =
A. B. − C.
e2 e 2
e D. e −
3.已知等比数列 a
n
的前n项和为 S
n
,若S =S +16S ,则公比q=
12 4 8
A.3 B. 2 C. 2 D.3
4.已知向量ABAC =6,线段 B C 的中点为 M ,且 A M = 6 ,则 BC =
A.2 30 B. 3 3 0 C. 2 2 6 D. 3 2 6
5.已知函数 f (x)=sin x+ (0) 的周期为
3
T
的最大值为
A.1 B.2 C.3 D.4
11 10 1
8.比较a= − ,b=ln1.2,c= 的大小
10 11 5e0.1
A.
,且满足T 2,若函数 f (x) 在区间
, 不单调,则的取值范围是
6 4
1 2 4
A. ,1 B. ,1 C. ,1 D. ,1 4 2 3 5
6.三棱锥A−BCD中,AB=3,BC =BD=4 2,ABC =ABD= ,DBC = ,则直线AD
4 3
与平面ABC所成角的正弦值是
4 17 4 29 3 17 3 29
A. B. C. D.
17 29 17 29
BD 1
7.已知三角形ABC中,BC =3,角A的平分线交BC于点D,若 = ,则三角形ABC面积
DC 2
a c b B. b c a C. b a c D. a b c
二、多项选择题:本题共4小题,每小题5分,共20分.在每小题给出的四个选项中,有多项符合
题目要求.全部选对得5分,部分选对但不全得3分,有错选的得0分.
9.已知实数abc满足 a b c ,且 a b c = 1 ,则下列说法正确的是
1
A.(a+c)2
b
C. a 2 b 2
B.
a
1
− c
b
1
− c
D. ( a2b−1 )( ab2 −1 ) 0
10.已知10个样本数据,若去掉其中最大和最小的数据,设剩下的8个样本数据的方差为 s 21 ,平均
数 x
1
;最大和最小两个数据的方差为 s 22 ,平均数 x
2
;原样本数据的方差为 S 2 ,平均数x,若
x
1
= x
2
,则
A.剩下的8个样本数据与原样本数据的中位数不变
B. x = x
1
C.剩下8个数据的下四分位数大于与原样本数据的下四分位数
4 1
D.S2 = s2 + s2
5 1 5 2
11.已知函数 f (x)=cos2x+2sinx ,则
A.函数 f (x) 在区间 , 上单调递增
6 2
B.直线x = 是函数 f (x) 图象的一条对称轴
2
3
C.函数 f (x) 的值域为 1,
2
D.方程 f (x)=a ( x(0,2)) 最多有8个根,且这些根之和为
x2
12.已知椭圆C: + y2 =1的中心为O, A,B是C 上的两个不同的点且满足OA⊥OB,则
2
A.点O在直线AB上投影的轨迹为圆
{#{QQABCQqQogAgABIAAQhCQQVCCkCQkBEACAoGAFAAIAABwQFABAA=}#}B.AOB的平分线交
第3页 共4页 第4页 共4页
A B 于D点, O D
6
的最小值为
3
2
C.AOB面积的最小值为
3
2 3
D.AOB中,AB边上中线长的最小值为
3
三、填空题:本题共4小题,每小题5分,共20分.
13.已知tan=2,则 s i n 4 = .
14.若 ( x2 −x−3 )5 =a +a x+a x2 + +a x10,则a +a +a +a +a = .
0 1 2 10 1 2 3 4 5
15.已知四棱锥的各个顶点都在同一个球面上.若该球的体积为 3 6 ,则该四棱锥体积的最大值
是 .
1 16.已知函数 f (x)=ex +msinx− x2 −(m+1)x+1,在
2
x = 0 处取到极小值,则实数 m = .
四、解答题:本题共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.(10 分)已知 a
n
是各项均为正数的等比数列,设c =log a ,若数列
n 3 n
c
n
的前 n 项和
n2 +n
S = .
n 2
(1)求数列
a
的通项公式; n
(2)记d =a ( 2n2 +6n+5 ) ,求数列
n n
d
n
的前n项和T .
n
18.(12 分)记 A B C 的内角 A,B,C的对边分别为 a , b , c ,已知c=2acosAcosB−bcos2A
(AB)
.
(1)求A;
(2)若D是 B C
乙类问题的概率为 0.5;C 员工能正确回答甲类问题的概率为 0.4,能正确回答乙类问题的概率
为0.75.
(1)求3人得分之和为20分的概率;
(2)设随机变量X为3人中得分为100的人数,求随机变量X的数学期望.
20.(12 分)已知四棱锥
上的一点,且BD:DC=1:2,AD=2,求a的最小值.
19.(12分)某单位组织知识竞赛,有甲、乙两类问题.现有A,B,C三位员工参加比赛,比赛规
则为:先从甲类问题中随机抽取一个问题回答,若回答错误则该员工比赛结束;若回答正确再从
乙类问题中随机抽取一个问题回答,无论回答正确与否,该员工比赛结束.每人两次回答问题的
过程相互独立.三人回答问题也相互独立.甲类问题中每个问题回答正确得20分,否则得0分;
乙类问题中每个问题回答正确得80分,否则得0分.已知A员工能正确回答甲类问题的概率为
0.5,能正确回答乙类问题的概率为 0.6;B 员工能正确回答甲类问题的概率为 0.6,能正确回答
S − A B C D 中,底面 A B C D 是矩形,
2
SA⊥BD,SA= AD= CD,M 是
2
S B 的中点.
(1)证明: M C ⊥ B D ;
(2)若 S A ⊥ A D , S A = 2 ,点 P 是 S C 上的动点,直线 A P 与平
面 A M C 所成角的正弦值为
1
1
0
0 ,求 S
S
P
C
.
x2 y2
21.(12分)已知椭圆C: + =1(b0)的左右焦点分别为F,F ,C是椭圆的中心,点M为
6 b2 1 2
其上的一点满足 MF MF =5, MC =2.
1 2
(1)求椭圆C的方程;
(2)设定点T(t,0) ,过点 T 的直线 l 交椭圆C于 P , Q 两点,若在C上存在一点 A ,使得直线 A P
的斜率与直线 A Q 的斜率之和为定值,求 t 的范围.
lnx
22.(12分)已知函数 f (x)=eax −e −ea(x0).
x
(1)当 a = 1
(第20题图)
f (x)
时,求函数g(x)=eax−1− +x−a的单调区间;
e
(2)证明:当a−e−2时,不等式 f (x)0恒成立.
{#{QQABCQqQogAgABIAAQhCQQVCCkCQkBEACAoGAFAAIAABwQFABAA=}#}中学生标准学术能力诊断性测试 2023 年 9 月测试
数学参考答案
一、单项选择题:本题共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.
1 2 3 4 5 6 7 8
B B B A C A C D
二、多项选择题:本题共4小题,每小题5分,共20分.在每小题给出的四个选项中,有多项
符合题目要求.全部选对的得5分,部分选对但不全的得3分,有错选的得0分.
9 10 11 12
ABD ABD BCD ABC
三、填空题:本题共4小题,每小题5分,共20分.
24
13.−
14.
25
第1页 共6页
− 4 6
64
15.
16.1
3
四、解答题:本题共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.(10分)
n2 +n (n−1)2 +n−1
(1) S = ,S = ,
n 2 n−1 2
S −S =n=c (n1,nN) ·································································· 2分
n n−1 n
又c =S =1,c =n ( nN+) ,a =3n ······················································· 3分
1 1 n n
(2) d =3n ( 2n2 +6n+5 ) =(n+1)2 +13n+1− ( n2 +1 ) 3n ····························· 7分
n
T = ( 22 +1 ) 32 − ( 12 +1 ) 3+ ( 32 +1 ) 33− ( 22 +1 ) 32 + +
n
( n2 +1 ) 3n −(n−1)2 +13n−1+(n+1)2 +13n+1− ( n2 +1 ) 3n
=− ( 12 +1 ) 3+(n+1)2 +13n+1
= ( n2 +2n+2 ) 3n+1−6 ····································································· 10分
18.(12分)
(1)
c=2acosAcosB−bcos2A(AB)
,
{#{QQABCQqQogAgABIAAQhCQQVCCkCQkBEACAoGAFAAIAABwQFABAA=}#}sinC=2sinAcosAcosB−sinBcos2A ···················································· 2分
sinC=sin2AcosB−sinBcos2A=sin(2A−B)0
··································· 4分
又
第2页 共6页
0 2 A − B ,则C =2A−B或 C + 2 A − B = ,
若 C = 2 A − B
,则A= ;
3
若 C + 2 A − B = ,则 A = 2 B ,又 A B ,不符合题意,舍去,
综上所述A= ························································································· 6分
3
2
2AB+ AC ( )2 2AB+ AC
(2) 2BD= DC,AD= , AD = ···························· 8分
3 3
b2+4c2+2bc=36 ①,又 a 2 = b 2 + c 2 − b c ②,
①
2
c c
4 +2 +1
36 4c2 +b2 +2bc b b
②得: = = ········································ 9分
a2 b2 +c2 −bc c 2 c
− +1
b b
c
令 = x,又AB,ab,a2 b2,b2 +c2 −bcb2,
b
c
cb,0 = x1,
b
4x2 +2x+1 6x−3
令 f (x)= (0 x1), f (x)=4+ ······························ 10分
x2 −x+1 x2 −x+1
t+3
令6x−3=t,x= ,
6
36t 36
f (t)=4+ (−3t 3), f (t)=4+ (−3t 3)
t2 +27 27 ,
t+
t
27 27 36 6 7
又t+ 12或t+ −12,1 f (t)7, 7,a ,
t t a2 7
6 7
所以当三角形ABC为等边三角形时a最小,最小值为 ····························· 12分
7
19.(12分)
(1)设事件 A
1
为A员工答对甲类问题;设事件A 为A员工答对乙类问题;
2
设事件B 为B员工答对甲类问题;设事件B 为B员工答对乙类问题;
1 2
{#{QQABCQqQogAgABIAAQhCQQVCCkCQkBEACAoGAFAAIAABwQFABAA=}#}设事件
第3页 共6页
C
1
为C员工答对甲类问题;设事件 C
2
为C员工答对乙类问题;
三人得分之和为20分的情况有:
①A员工答对甲类题,答错乙类题;B与C员工均答错甲类题,
则P ( A A B C ) =P(A )P ( A ) P ( B ) P ( C ) =0.50.40.40.6=0.048
1 2 1 1 1 2 1 1
·············································································································· 2分
②B员工答对甲类题,答错乙类题;A与C员工均答错甲类题,
P ( B B A C ) =P(B )P ( B ) P ( A ) P ( C ) =0.60.50.50.6=0.09
1 2 1 1 1 2 1 1
·············································································································· 4分
③C员工答对甲类题,答错乙类题;A与B员工均答错甲类题,
P ( C C A B ) =P(C )P ( C ) P ( A ) P ( B ) =0.40.250.50.4=0.02,
1 2 1 1 1 2 1 1
所以三人得分之和为20分的概率为0.048+0.09+0.02=0.158 ·································· 6分
(2) A员工得100分的概率为P(A A )=P(A)P(A )=0.3,
1 2 1 2
B员工得100分的概率为P(B B )=P(B )P(B )=0.3,
1 2 1 2
C员工得100分的概率为P(C C )=P(C )P(C )=0.3,
1 2 1 2
·············································································································· 9分
X ~ B(3,0.3) ······················································································ 11分
E(X)=30.3=0.9 ············································································ 12分
20.(12分)
(1)取AB的中点N,连接MN,NC,则线段MN为三角形SAB的中位线,
MN SA,又SA⊥BD,BD⊥MN ························································ 2分
设直线CN与直线BD交于Q点,
NQ BQ 1
则BNQ CDQ, = = ,
NC BD 3
6 6
设AD=a,CD= 2a,NC = a,NQ= a,
2 6
3
同理BD= 3a,BQ= a,
3
a2 a2 a2
又NQ2 +BQ2 = + = = BN2 ··························································· 5分
6 3 2
BD⊥CN,BD⊥面MNC,MC⊥BD ··················································· 6分
{#{QQABCQqQogAgABIAAQhCQQVCCkCQkBEACAoGAFAAIAABwQFABAA=}#}(2)分别以直线AD,AB,AS为x轴,y轴,z轴建立直角坐标系,
( ) ( ) ( )
则A(0,0,0),S(0,0,2),C 2,2 2,0 ,B 0,2 2,0 ,M 0, 2,1 ,
设
第4页 共6页
S P S C = ,
( ) ( )
P 2,2 2,2(1−) ,AP= 2,2 2,2(1−) ································· 8分
( ) ( )
又AM = 0, 2,1 ,AC = 2,2 2,0 ,
设平面AMC的法向量 n = ( x , y , z ) ,
nAM = 2y+z =0
( )
则 ,n= − 2,1,− 2 ·········································· 10分
nAC =2x+2 2y =0
设直线AP与平面AMC所成的角为,
2 2(1−)
10
则sin= cos AP,n = = ,
5 162 −8+4 10
1 SP 1
= , = ·················································································· 12分
2 SC 2
21.(12分)
(1)设 MF =r, MF =r ,在
1 1 2 2
M F
1
F
2
中,设FMF =,
1 2
FF 2 =r2 +r2 −2rr cos=4c2,
1 2 1 2 1 2
1( )
2rr cos=r2 +r2 −4c2,又MC = MF +MF ,
1 2 1 2 2 1 2
MC 2 = 1( MF 2 +MF 2 +2MF MF ) = 1 ( r2 +r2 +2rr cos ) = r 1 2 + r 2 2 −c2,
4 1 2 1 2 4 1 2 1 2 2 2
r2 r2 (r +r )2 −2rr
MC2 = 1 + 2 −c2 = 1 2 1 2 −c2 =2a2 −c2 −5=4 ························· 3分
2 2 2
2a2 −c2 =9, a2 =6,c2 =3,b2 =3,
x2 y2
所以椭圆C的方程为: + =1 ······························································· 4分
6 3
(2)设A(x ,y ),P(x,y ),Q(x ,y ) ,直线l的方程为x=y+t,
0 0 1 1 2 2
{#{QQABCQqQogAgABIAAQhCQQVCCkCQkBEACAoGAFAAIAABwQFABAA=}#}x2 y2
6 + 3 =1 ( 2 +2 ) y2 +2ty+t2 −6=0,
x=y+t
2t t2 −6
y + y =− ,y y = ,x =y +t,x =y +t,
1 2 2 +2 1 2 2 +2 1 1 2 2
4t 2t2 −62
x +x = ,x x = ································································ 7分
1 2 2 +2 1 2 2 +2
y −y y −y (y −y )(x −x )+(y −y )(x −x )
设 0 1 + 0 2 = 0 1 0 2 0 2 0 1
x −x x −x (x −x )(x −x )
0 1 0 2 0 1 0 2
2x y −y (x +x )+2y y +(t−x )(y + y )
= 0 0 0 1 2 1 2 0 1 2
x2 −(x +x )x +x x
0 1 2 0 1 2
2x y2 +(2tx −12)+4y (x −t)
= 0 0 0 0 0 = p
( x2 −6 ) 2 +2(x −t)2
0 0
若p为常数,则2tx −12=0 ····································································· 10分
0
2x y 4y (x −t) 2y
即6=tx
0
,而此时
( x2
0
−6
0
)
=
2(
0
x −
0
t)2
=
x −
0
t
,
0 0 0
6
又− 6 x 6,− 6 6,即t 6或
0 t
第5页 共6页
t − 6 ,
综上所述, t 6 或 t − 6
6 18
,存在点A , 3− ,使得直线AP的斜率与直线AQ
t t2
2y
的斜率之和为定值 0 ············································································ 12分
x −t
0
22.(12分)
lnx (1−lnx) 1−lnx+x2
(1)g(x)= +x,g(x)= +1= ······································ 1分
x x2 x2
1 2
令h(x)=1−lnx+x2,h(x)=− +2x0,即x ,
x 2
2 2
所以函数h(x) 在区间 ,+单调递增,在区间0, 单调递减 ················· 3分
2 2
{#{QQABCQqQogAgABIAAQhCQQVCCkCQkBEACAoGAFAAIAABwQFABAA=}#} 2
又h (x)=h 0,h(x)0,g(x)0,
min 2
所以函数g(x)
在
(0,+)
上单调递增 ····························································· 5分
lnx
(2)不等式eax −e −ea0等价于
x
第6页 共6页
x e a x − 1 − l n x − a x 0
1
令g(x)= xeax−1−lnx−ax0,g(x)= (1+ax)( xeax−1−1 ) ···························· 7分
x
设h(x)=xeax−1−1,h(x)=(ax+1)eax−1,
1
当0 x− ,h(x)0,
a
所以函数 h ( x )
1
在 0,− 上单调递增,在
a
−
1
a
, +
上单调递减,
h (x)=h − 1 =− 1 ( e−2 +a ) ,
max a a
1
a−e−2,h =− ( e−2 +a ) 0,
max a
所以函数 g ( x )
1
在 − ,+ 单调递增,在
a
0 , −
1
a
单调递减 ··························· 10分
1 1 −1
g (x)= g
−
=− e−2 −ln −1,
min a a e2a
−1 1
令 =t,则g (t)=t−lnt−1=m(t)( t(0,1)) ,m(t)=1− ,
e2a min t
m(t)
在
(0,1)
单调递减,在
(1,+)
单调递增,
m (x)=m(1)=0,m(t)0,
min
g (x)0,g(x)0 ········································································ 12分
min
即a−e−2时,不等式 f (x)0恒成立.
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