绝密★启用并使用完毕前
2022一2023学年高三上学期期中考试
数学试题
证单的(生)1心()
本试卷共4页,22题,全卷满分150分。考试用时120分钟。
(代S).
注意事项:
1,答卷前,考生务必将自己的姓名、座号、考试号填写在答题卡上。{。五
2.回答选择题时,选出每小题答案后,用铅笔把答题卡上对应题目的答案标号涂黑。如需改
动,用橡皮擦干净后,再选涂其他答案标号。回答非选择题时,将答案写在答题卡上。写在
本试卷上无效。
,2四页n洁阳,心)校这:面不
.S
3.考试结束后,将本试卷和答题卡一并交回。
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.已知集合A={x|-1≤x≤1),B={x|x2-2x≤0,x∈Z},则AQB=与
A.{0,1}
B.[-1,2]
C.[0,1]
D.{-1,0,1,2}
2.已知点0是平面内任意一点,则“存在t∈R,使得OC=(1上)OA+tO”是“A,B,C
三点共线”的
9· 9意日拉:5面()
A.充分不必要条件
B必要不充分条件平(.),塘函的(C
C.充要条件
D.既不充分又不必要条件
3.已知等比数列{an},a3a1oa1 =8,则a10=
A.1
B.2
C.4
D.8
4.三角形的三边分别为a,b,c,秦九韶公式S-√2-十
和海伦公式
2
S=√pp-a)p-b)p-C)(力=a++C)是等价的,都是用来求三角形的面积,印
2
度数学家婆罗摩笈多在公元7世纪的一部论及天文的著作中,给出若四边形的四边分别为
a,b,c,d,则S=√p-a)(的-b)p-c(p-d)-abcd cos0(p=a+b↓c+d,0
2
为一组对角和的一半).已知四边形四条边长分别为3,4,5,6,则四边形最大面积为
A.21
B.410
C.105
D.6√10
5.已知0为第三象限角,sin0一cos0=一
,则cos9(1-2sin20)
1
sin0+cose
A-
B.3
c爱
4
0.26
高三数学试题:第1页(共4页)
可日
0000000
6.函数f(x)=一e3x十2ex的图象大致为
。然共,代己心法,小↓共盟本:疆空就,三
,S)D联5.8
函快S.
A
B
D
7.在△ABC中,内角A,B,C所对的边分别为a,b,c,且b二6,c二4,点0为外心,则
AO.BC=
A.-20
、)梁成.
1.}暖落.8
B.-10
C.10.1)
D.20
8.设方程e十x十e=0和lnx十x十e=0的根分别为力和q,函数f(x)=e+(力十g)x,则
Af(宁)Bf(导)之武时见红游馆【.D
C.f(径)共腿本:國答聊,四
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,部分选对的得2分,有选错的得0分。(》西
9.方程√3sin2x十cos2x=2在区间[0,2π]上有解,则解可能为i小疑始()1来(I)
A.
清尘新B,行租1袋周#评,C,石平向共D
2π
7π
5
「)1=部(
10已知等差数列a】,前n吸和为5.,@之0,器-1,则下列结论正确的是,
A.a2022>0
B.Sm的最大值为S2023
C.|am|的最小值为a2o2z
D.S4o44<0
(代3).8
11.已知a>0,b>0,2a+b=1,则下列不等式一定成立的是
A+≥9
“品其,氏爱弹的五六出含虽
B.b≤1发民爱送w要{}联口
a
0·[十0=0,{=:0=1m
ca2+82≥号
D.V2a+√6≤√2{d}·{,}藏果(I)
l2.在△ABC中,内角A,B,C所对的边分别为a,b,c,且tan(A十B)(1-tanAtanB)=
√5c
:闻闻长兰,
,则下列结论正确的是
acosB
AA=若
(s1).o1
C)s自·力。d,民眼设暗该两门·日·6武内,中门8A
B.若6-c=
3a,则△ABC为直角三角形
;8n龙=A6:分()
C,若△ABC面积为1,则三条高乘积平方的最大值为3√3
.日农,=店一g(
D,若D为边BC上一点,且AD=1,BD:DC=2c:b,则2b十c的最小值为9y7
7
高三数学试题第2页如(共4页)
可日
0000000绝密★启用并使用完毕前
2022-2023学年高三上学期期中考试
数学试题参考答案 2022.11
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.
题号 1 2 3 4 5 6 7 8
答案 A C B D B A C B
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,部分选对的得 2 分,有选错的得 0 分.
题号 9 10 11 12
答案 AC ACD BCD CD
三、填空题:本题共 4 小题,每小题 5分,共 20分.
3 10
13. 14. 1,2 4, 15. 68 16. , 22023 1
5 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)
解析:(1) f (x) 1 cos 2x 3 sin 2x ····································································· 2 分
π
2sin(2x ) 1 ············································································· 4 分
6
所以T 2π
2 ····················································································· 5 分
(2)将 y f (x) π 向右平移 个单位得到 y 2sin(2x ) 1 ·····································6 分
6 6
1
再将图象上所有点的横坐标缩短到原来 倍(纵坐标不变),
2
得到 y 2sin(4x ) 1 ,所以 g(x) 2sin(4x ) 1 ····································7 分
6 6
由 4x k (k Z) k ,得 x (k Z) ,
6 2 6 4
g(x) k 所以 对称轴为 x (k Z) ··························································10 分
6 4
18.(12 分)
解析:(1)设数列 an 的公差为 d,数列 bn 的公比为 q (q 0) ,
高三数学试题 第 1页 共 7页
a1 d b1q 1 ,
由题意可得 ·························································· 2 分
a
2
1 3d b1(1 q q ),
d q ,
即为
q2 q 3d ,
所以 q2 2q q(q 2) 0,
因为 q 0,所以 q d 2,···································································· 4 分
所以 an 2n 1, b 2
n 1, n n .···························································· 6 分
2n 1 , 当n为奇数时 ,
(2)由(1)可得 cn
2n 1 , 当n为偶数时.
所以数列 cn 的奇数项是以1为首项, 4 为公差的等差数列,
数列 cn 的偶数项是以 2 为首项, 4 为公比的等比数列,···························· 8 分
且 cn 前 11 项中有 6 项奇数项,5 项偶数项,
T 6 1 6(6 1) 4 2(1 4
5 )
所以 11 ························································· 10 分2 1 4
211 196
748.······································································· 12 分
3
19.(12 分)
解析:(1)法 1:
由 2(acosB bcos A) c,
得 2(sin AcosB sin Bcos A) sinC ,··················································1 分
因为 A B C ,
所以 sinC sin(A B) ,
则 2(sin AcosB sin Bcos A) sin AcosB sin Bcos A,····························· 3 分
所以 sin AcosB 3sin Bcos A,··························································· 4 分
ABC A B 因为 中 和 都不能为 ,
2
sin A sin B
所以 3 ,······································································· 5 分
cos A cosB
所以 tan A 3tan B ··········································································· 6 分
法 2:
由射影定理 a cosB bcos A c ,代入,
得 2(acosB bcos A) acosB bcos A ··················································1 分
即 a cosB 3bcos A ·········································································· 3 分
所以 sin AcosB 3sin Bcos A,··························································· 4 分
因为 ABC 中 A和 B都不能为 ,
2
高三数学试题 第 2页 共 7页
sin A
所以 3 sin B ,······································································· 5 分
cos A cosB
所以 tan A 3tan B ··········································································· 6 分
(2)法 1:
2 2 2 2 2 2
由 cosB a c b , cos A b c a ,代入(2 acosB bcos A) c
2ac 2bc
得 2(a2 b2 ) c2 ,···········································································7 分
因为 a2 b2 bc,所以 2bc c2 ,即 2b c,········································ 9 分
代入 a2 b2 bc或 2(a2 b2 ) c2 ,
3
得 a c2 ,·················································································· 10 分
3 2 2 1 2
a2 c2 b2 ( c) c ( c)cosB 2 2 3由余弦定理, 2ac 2 ,
2 3 c c
2
B π所以
6 ····················································································· 12 分
法 2:
a2 c2cosB b
2 2 2 2
由 , cos A b c a ,代入(2 acosB bcos A) c
2ac 2bc
得 2(a2 b2 ) c2 ,···········································································7 分
因为 a2 b2 bc,所以 2bc c2 ,
即 2b c,即 2sin B sinC ································································9 分
由(1)知, sin AcosB 3sin Bcos A,
而 2sin B sinC sin(A B)=sin AcosB sin Bcos A,上式代入,
得 2sin B 4sin Bcos A,
cos A 1 π所以 ,所以 A ,·····························································10 分
2 3
由 tan A 3tan B 知, tan B 3 ,
3
π
所以 B ····················································································· 12 分
6
法 3:
由余弦定理 a2 b2 c2 2bc cosA,代入 a2 b2 bc,
得 c2 2bc cos A bc,···································································· 7 分
所以 c 2bcos A b,
所以 sinC 2sin Bcos A sin B ,·························································8 分
即 sin(A B) 2sin Bcos A sin B ,
即 sin AcosB sin Bcos A sin B,
高三数学试题 第 3页 共 7页
即 sin(A B) sin B,······································································· 9 分
所以 A 2B或 A B B,
因为 A 0, ,所以 A 2B ······························································ 10 分
代入 tan A 3tan B 2 tan B, tan A tan 2B 3tan B ,
1 tan 2 B
因为 tan B 0,所以 tan2 B 1 ,
3
因为 tan A , tan B同号,所以 tan B 0 ,
所以 tan B 3 ,
3
因为 B (0 , ) ,所以 B ····························································12 分
6
法 4:
2 2 2 2 2 2
由 cosB a c b , cos A b c a ,代入(2 acosB bcos A) c
2ac 2bc
a2 b2 1得 c2 ,············································································ 7 分
2
因为 2(acosB bcos A) c,
1
所以 a2 b2 c2 c(a cosB b cosA) bc ,·········································8 分
2
所以 sin AcosB sin Bcos A sin B
即 sin(A B) sin B,······································································· 9 分
所以 A 2B或 A B B,
因为 A 0, ,所以 A 2B ······························································ 10 分
代入 tan A 3tan B 2 tan B, tan A tan 2B 3tan B ,
1 tan 2 B
tan B 0 tan2 B 1因为 ,所以 ,
3
因为 tan A , tan B同号,所以 tan B 0 ,
3
所以 tan B ,
3
因为 B (0 , ) ,所以 B ····························································12 分
6
20.(12 分)
5 1
解析:(1)由题意知 当 a 3 时, f (x) x3 x2 2x
2 2
f (x) 3x2 5x 2 ,
f (1) 3 12 5 1 2 6 ,······································································2 分
高三数学试题 第 4页 共 7页
f (1) 13 5 12 2 1 1 1,
2 2
所以切线方程为 y 1 6(x 1) ,即 y 6x 5 ·············································4 分
(2) f (x) ax2 (2a 1)x 2 (x 2)(ax 1) (a 0) ·······································6 分
①当 a 0时,
f (x) 0 1 得 x 2或x ; f (x) 0 得 2 1 x .
a a
所以 f (x) 在 ( , 2), ( 1 , ) 1上单调递增,在 ( 2, ) 上单调递减.
a a
当 a 0 时,
1 1
②当 2 ,即 a 时,
a 2
f (x) 0 恒成立, f (x) 在 ( , ) 上单调递减.
1 1
③当 2 ,即 a 时,
a 2
f (x) 0 得 x 2或x 1 ; f (x) 0 得 2 x 1 .
a a
所以 f (x) 在 ( , 2), ( 1 , ) 1 上单调递减,在 ( 2, ) 上单调递增.
a a
1 1
④当 2 ,即 a 0时,
a 2
f (x) 0 得 x 1 1 或x 2 ; f (x) 0 得 x 2 .
a a
所以 f (x) ( , 1在 ), ( 2, ) 上单调递减,
a
在 (1 , 2) 上单调递增. ········································································10 分
a
1
综上: a 0时, f (x) 在 ( , 2), ( , ) 上单调递增,在 ( 2, 1) 上单调递减.
a a
a 1 时, f (x) 在 ( , ) 上单调递减.
2
a 1 1 1 时, f (x) 在 ( , 2), ( , ) 上单调递减,在 ( 2, ) 上单调递增.
2 a a
1
a 0 f (x) ( , 1), ( 2, ) 1 时, 在 上单调递减,在 ( , 2) 上单调递增········12 分
2 a a
21.(12 分)
解析:(1)因为 na 2 2n 1 (n 1)an n
2 n(n N ) ,两端同除 n(n 1)
a 2 a 2
可得: n 1 n 1,··········································································· 3 分
n 1 n
高三数学试题 第 5页 共 7页
a 2
又 a1 1,所以
n 是首项为 1,公差为 1的等差数列·································4 分
n
a 2
所以 n n,
n
因为数列{an} 是正项数列,所以 an n.·················································· 5 分
1
(2) bn , ·························································································6 分2n n
n 1 S b 1 3当 时, 1 1 ,··································································· 7 分2 2
当 n≥2 b 1 1 1 n n 1时, n ,
2 a 3 n( n n) n( n n 1) nn
b n n 1 1 1所以 n ,·························································· 9 分n n 1 n 1 n
S 1 1 1 1 1 1 3 1 3n (1 ) ( ) ( ) 2 2 2 3 n 1 n 2 n 2
综上, S 3n ························································································12 分2
22.(12 分)
a 1 x 2 ax 1
解析:(1) f ( x ) 1
x x2 x2
, f (1) 0
(i)当 a≤0 时,
2
x≥1, f ( x ) a 1 1 x ax 1
x x2 x2
≤0 ,
函数 f ( x ) 在 1, 单调递减,所以 f ( x )≤0恒成立;
(ii)当 0 a≤2时,
a 1 x 2 ax 1
≤0 , f ( x ) 1 2 ≤0 ,x x x2
函数 f ( x ) 在 1, 单调递减,所以 f ( x )≤0恒成立;
(iii)当 a 2时,
x2 ax 1 0 有两根 x1 , x2 且 x1x2 1 .
不妨设 x1 1 x2 ,则函数 f ( x ) 在 1, x2 单调增,
这与 f ( x )≤0矛盾,所以不成立,
综上可得 a≤2 . ····················································································4 分
1 1
(2)由(1)可知 x 1, ln x (x ) ,
2 x
高三数学试题 第 6页 共 7页
x 1 1令 , k * ,
k
则 ln(1 1 ) 1 ( k 1 k ) 1 1 1 ( )
k 2 k k 1 2 k k 1
令 k 1,2,3, ,n得
ln 1 1 1 (1 1 ) ,
2 1 2
ln(1 1 ) 1 (1 1 ) ,...
2 2 2 3
ln(1 1) 1 (1 1 ) ,
n 2 n n 1
对以上各式累加可得:
ln 1 1 ln(1 1) ln(1 1 1 1 1 1 1 1 ) ( )
2 n 2 2 3 n 2 n 1
ln n 1 1 1 1 1 n
2 3 n 2(n 1)
1 1 1 1 n
即对任意 n * , e 2 3 n 2(n 1) n 1. ·················································8 分
(3)由(1)知,当 a≤2 时, f ( x ) 在 0, 单调递减,且 f (1) 0 ,
所以只有一个零点,
当 a 2时,
f ( x ) 在(0,x1)单调递减, f ( x ) 在(x1,1)单调递增,
又因为 f (1) 0 ,所以 f x1 0 .
a a2
因为 x 4 2 11 ,2 a a2 4 a
1 1 1
, f ( ) a(ln 1 1 2a) ,
2a2 a 2a2 2a2 2a3
1 1 l2(a4 a3) 1
令 g(a ) ln 2a,则 g (a ) 0 ,
2a2 2a3 6a4
g(2) 1 1 ln 4 0 ,
8 16
a 2 f ( 1 ) a(ln 1 1当 时, 2 2 2a) 0 ,2a 2a 2a3
( 1 2 , x ),f ( ) 0 ,2a 1
又 f ( x ) 1 1 1 f ( ),所以 (1,2a2 ),f ( ) 0 ,
x
此时有 3 个零点.
综上,当 a≤2 时, f ( x ) 只有一个零点,
当 a 2时, f ( x ) 有 3 个零点.······························································ 12 分
高三数学试题 第 7页 共 7页