高一数学第 1 页 共 4 页
2019-2020 学年度第一学期期中学业水平检测
高一数学 2019.11
本试卷 4 页,23 小题,满分 150 分.考试用时 120 分钟.
第Ⅰ卷
一、单项选择题:本大题共 10 小题,每小题 4 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 2{ | 2 8 0}A x x x , { | 2 1 0}B x x ,则 A B I ( )
A. )2,( B. )2
1,2( C.(4,+ ) D. )4,2
1(
2.函数 4( ) 1
xf x x
的定义域为( )
A. ( ,4] B. ( ,1) (1,4] C. ( ,1) (1,4) D. (0,4)
3.“ R, | | 0x x x ”的否定是( )
A. R, | | 0x x x B. R, | | 0x x x
C. R, | | 0x x x D. R, | | 0x x x
4.下列函数既是奇函数又在 (0, ) 上单调递减的是( )
A. y x B. 3y x C. 1y x D. 2y x
5.“ 4a ”是“关于 x 的方程 2 0( R)x ax a a 有实数解”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
6.已知函数
2 , 0
( ) 1( ) , 02
x
xxf x
x
,则 ( (2))f f ( )
A. 4 B. 1
2
C. 1
2 D. 8
7.已知 ( )f x 为定义在 R 上的偶函数,当 0x 时, ( ) 2xf x ,则 ( )f x 的值域为( )
A.[1 ) , B. (0,1) C. (0,1] D. ( ,1]高一数学第 2 页 共 4 页
8.已知 0.22a , 0.32b , 0.30.2c 则( )
A.b a c B. a b c C.b c a D. a c b
9.为了保护水资源,提倡节约用水,某城市对居民生活用水实行“阶梯水价”.计费方法如下:
每户每月用水量 水价
不超过 312m 的部分 3 元 3/m
超过 312m 但不超过 318m 的部分 6 元 3/m
超过 318m 的部分 9 元 3/m
若某户居民本月交纳的水费为54 元,则此户居民本月用水量为( )
A. 320m B. 318m C. 315m D. 314m
10 . Rx , 用 函 数 ( )M x 表 示 函 数 ( )f x x , 2( )g x x 中 较 大 者 , 记 为
( ) m ax{ ( ), ( )}M x f x g x ,则 ( )M x 的值域为( )
A. (1, ) B. (0, ) C.[1 ) , D.[0 ) ,
二、多项选择题:本大题共 3 小题,每小题 4 分,共 12 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 4 分,选对但不全的得 2 分,有选错的得 0 分。
11.已知 , ,a b c 为实数,且 0a b ,则下列不等式正确的是( )
A. 1 1
a b
B. 22 bcac C.
b
a
a
b D. 22 baba
12.狄利克雷函数 ( )f x 满足:当 x 取有理数时, ( ) 1f x ;当 x 取无理数时, ( ) 0f x .则
下列选项成立的是( )
A. 0)( xf B. 1)( xf
C. 0)( 3 xxf 有1个实数根 D. 0)( 3 xxf 有 2 个实数根
13.已知定义在 R 上函数 ( )f x 的图象是连续不断的,且满足以下条件:① Rx ,
( ) ( )f x f x ; ② 1 2, (0, )x x , 当 1 2x x 时 , 都 有 2 1
2 1
( ) ( ) 0f x f x
x x
; ③
( 1) 0f .则下列选项成立的是( )
A. (3) ( 4)f f B.若 ( 1) (2)f m f ,则 ( ,3)m
C.若 ( ) 0f x
x
, ( 1,0) (1, )x D. Rx , RM ,使得 ( )f x M高一数学第 3 页 共 4 页
第Ⅱ卷
三、填空题:本大题共 4 个小题,每小题 4 分,共 16 分。
14.已知函数 1( ) 1xf x a ( 0a 且 1a ),则函数 ( )f x 的图象恒过定点 .
15.已知函数 3( ) 3cf x ax bx x
,若 ( ) 4f t ,则 ( )f t .
16.已知函数 2( )f x x bx c ,若 (1) (2) 0f f ,则 ( 1)f .
17.将“ 24 16 ”中数字“ 4 ”移动位置后等式可以成立,如:“ 24 16 ”.据此,
若只移动一个数字的位置使等式“ 23 16 4 ”成立,则成立的等式为 .
四、解答题:共 82 分。解答应写出文字说明,证明过程或演算步骤。
18.(12 分)已知全集 RU ,集合 0{ R|2 1 3 }A x x ,集合 1{ R| 2 4}2
xB x .
(1)求 BA 及 R( )C A B ;
(2)若集合 { R| 2 , 0}C x a x a a ,C B ,求实数 a 的取值范围.
19.(14 分)已知函数 )(xf 为定义在 R 上的奇函数,当 0x 时, 2
1)( xxxf .
(1)求 ( 2)f 的值;
(2)用函数单调性的定义证明:函数 )(xf 在 ),0( 上单调递增;
(3)求函数 )(xf 在 Rx 上的解析式.
20.(14 分)已知函数 ( ) 2 xf x .(1)求
2
3
2(0) 2 2 2f
的值;
(2)若函数 ( ) ( ) ( )h x f x g x ,且 ( ), ( )h x g x 满足下列条件:① ( )h x 为偶函数;
② ( ) 2h x 且 Rx 使得 ( ) 2h x ;③ ( ) 0g x 且 ( )g x 恒过 (0,1) 点.
写出一个符合题意的函数 ( )g x ,并说明理由.高一数学第 4 页 共 4 页
21.(14 分)已知函数 2( ) ( 1) 1f x ax a x , Ra .
(1)若不等式 ( ) 0f x 的解集为 1( ,1)2 ,求 a 的值;
(2)若 0a ,讨论关于 x 不等式 0)( xf 的解集.
22.(14 分)已知二次函数 2( ) 1( R)f x x kx k .
(1)若 ( )f x 在区间[2 ) , 上单调递增,求实数 k 的取值范围;
(2)若 2k ,当 [ 11]x , 时,求 (2 )xf 的最大值;
(3)若 ( ) 0f x 在 (0 )x , 上恒成立,求实数 k 的取值范围.
23.(14 分)
现对一块边长8 米的正方形场地 ABCD 进行改造,点 E 为线段 BC 的中点,点 F 在
线段 CD 或 AD 上(异于 CA, ),设| |AF x (米), AEF 的面积记为 )(1 xfS (平
方米),其余部分面积记为 2S (平方米).
(1)当 10x (米)时,求 )(xf 的值;
(2)求函数 )(xf 的最大值;
(3)该场地中 AEF 部分改造费用为
1
9
S (万元),其余部分改造费用为
2
25
S (万元),
记总的改造费用为W (万元),求W 取最小值时 x 的值.高一数学答案第 1 页 共 4 页(数学是有生命的,题目是有经典的)
2019-2020 学年度第一学期期中学业水平检测
高一数学参考答案
一、单项选择题:本大题共 10 小题,每小题 4 分,共 40 分。
1 10:D B B C A D C A C D
二、多项选择题:本大题共 3 小题,每小题 4 分,共 12 分。
11.ACD; 13.CD;
三、填空题:本大题共 4 个小题,每小题 4 分,共 16 分。
14. (1,2) ; 15. 2 ; 16. 6 ; 17. 32 16 4 ;
四、解答题:共 82 分。解答应写出文字说明,证明过程或演算步骤。
18.(12 分)解:(1)由 02 1 3 1x 得 1x ,所以 { | 1}A x x ······················1 分
由 1 2 42
x 即 1 22 2 2x 得 1 2x ,所以 { | 1 2}B x x ····················3 分
所以 { | 1 1}A B x x ···········································································5 分
( ) { | 1}RC A x x ······················································································· 6 分
( ) { | 1}RC A B x x ··············································································· 7 分
(2)因为C B ,且 0a
所以 2 2a , 1a ·····················································································10 分
故所求 a 的取值范围为: 0 1a ··································································12 分
19.(14 分)解:(1)因为当 0x 时, 2
1)( xxxf
所以 2
1 7(2) 2 2 4f ················································································· 2 分
又因为 )(xf 为奇函数,所以 4
7)2()2( ff ·············································4 分
(2) 1 2, (0, )x x , 1 2x x ·····································································5 分
则 2
2
2
1
2
2
2
1
212
1
2
2
2121 )(11)()( xx
xxxxxxxxxfxf
1 2 1 2 1 2
1 2 1 22 2 2 2
1 2 1 2
( )( )( ) ( )(1 )x x x x x xx x x xx x x x
····················8 分
因为 1 2, (0, )x x ,所以 1 2
2 2
1 2
1 0x x
x x
;因为 1 2x x ,所以 1 2 0x x ··············9 分
所以 0)()( 21 xfxf ,即 1 2( ) ( )f x f x
所以函数 )(xf 在 ),0( 上单调递增·······························································10 分
12.ABC;高一数学答案第 2 页 共 4 页(数学是有生命的,题目是有经典的)
(3)当 0x 时, 0 x
所以 2 2
1 1( ) ( ) [( ) ]( )f x f x x xx x
·············································12 分
又因为 0)0( f ························································································· 13 分
所以函数 )(xf 在 Rx 上的解析式为:
2
2
1 , 0
( ) 0, 0
1 , 0
x xx
f x x
x xx
···························· 14 分
20.(14 分)解:(1)由题意知:
2
3
2(0) 2 2 2f
3 1 3 1 20 2 02 2 2 22 2 2 2 1 2 1 2 0
·············································· 4 分
(2)函数 xxg 2)( ···················································································· 6 分
证明如下: ① xxxh 22)( ,所以 )(2222)( )( xhxh xxxx
所以 xxxh 22)( 为偶函数···················································· 9 分
② 2222222222)( 0 xxxxxxxh ····················12 分
当且仅当 xx 22 ,即 0x 时等号成立····································13 分
③ ( ) 2 0xg x , ( )g x 恒过 (0,1) 点··········································· 14 分
21.(14 分)解:(1)因为 ( ) 0f x 的解集为 1( ,1)2 ,
所以 1 ,12 为方程 ( ) 0f x 的两个根·································································· 3 分
由韦达定理得:
1 1
2
1 3
2
a
a
a
,解得 2a ··························································· 5 分
(2)由 ( ) 0f x 得: 2 ( 1) 1 0ax a x ,所以( 1)( 1) 0ax x ····················· 7 分
①当 10 a 时, 11
a ,不等式的解集是{ | 1x x 或 1}x a
······························ 9 分
②当 1a 时,不等式可化为 0)1( 2 x ,不等式的解集是{ | 1}x x ··················· 11 分
③当 1a 时, 110
a ,不等式的解集是 1{ |x x a
或 1}x ··························· 13 分
综上可得,当 10 a 时,不等式的解集是{ | 1x x 或 1}x a
;当 1a 时,不等式的解
集是{ | 1}x x ;当 1a 时,不等式的解集是 1{ |x x a
或 1}x ··········14 分高一数学答案第 3 页 共 4 页(数学是有生命的,题目是有经典的)
22.(14 分)解:(1) 若 ( )f x 在 2x , 单调递增,则 22
k , 4k ········ 4 分
(2)当 2k 时, 2( ) 2 1f x x x
令 2xt ,因为 [ 11]x , ,所以 1[ ,2]2t
所以 2 2(2 ) ( ) 2 1 ( 1)xf f t t t t ···························································· 6 分
所以 2( ) 2 1f t t t 在 1[ 1]2
, 上单调递减,[1,2] 上单调递增,
又 1 1( ) (2) 12 4f f ·············································································· 8 分
m ax m ax(2 ) ( ) (2) 1xf f t f ·····································································9 分
(3)因为 ( ) 0f x 在 (0 )x , 上恒成立,
所以 2 1 0x kx 在 (0 )x , 恒成立,
即 1k x x
在 (0 )x , 恒成立·································································· 11 分
令 1( )g x x x
,则 2121)(
xxxxxg ,当且仅当 1x 时等号成立·········· 13 分
2k ·····································································································14 分
23.(14 分)解:(1)由题知:当 810 x 米时,点 F 在线段CD 上,
6810 22 DF ····················································································1 分
所以 ADFECFABEABCDABCD SSSSSSS 21 ··········································· 2 分
所以 1 (10) 64 16 4 24 20S f (平方米)·············································3 分
(2)由题知,当 8x (米)时,点 F 在线段 AD 上··········································4 分
此时: 321 ADESS (平方米)···································································5 分
当 8x (米)时,点 F 在线段CD 上, [8,8 2)x ,
令 2 64 [0,8)t DF x ········································································ 6 分
所以 1 2ABCD ABCD ABE ECF ADFS S S S S S S
所以 2 2
1 ( ) 64 16 2(8 64) 4 64S f x x x
232 2 64 32 2x t ···································································8 分
因为 [0,8)t ,所以 322321 tS ,等号当且仅当 0t 时,即 8x 时取得
所以 ( )f x 最大值为32 ·················································································· 9 分高一数学答案第 4 页 共 4 页(数学是有生命的,题目是有经典的)
(3)因为 6421 SS
所以: 1 2
1 2 1 2
( )9 25 9 25( ) 64
S SW S S S S
2 1 2 1
1 2 1 2
9 25 9 251 1[34 ( )] [34 2 ] 164 64
S S S S
S S S S
(万元)··················· 10 分
等号当且仅当
2
1
1
2
21
259,64 S
S
S
SSS 时取得,即 241 S 时取得······················· 11 分
当 8x (米)时,点 F 在线段 AD 上, 6,2441 xxS ·······························12 分
当 8x (米)时,点 F 在线段CD 上, 2
1 32 2 64 24, 4 5S x x ··········13 分
综上的W 取最小值时 6x 或 4 5x ··························································· 14 分