当前位置:文档之家› 2016年学业水平考试数学答案

2016年学业水平考试数学答案

2016年学业水平考试数学答案
2016年学业水平考试数学答案

机密★启用并使用完毕前

山东省2016年冬季普通高中学业水平考试

数学试题参考答案及评分标准

第Ⅰ卷(共 60 分)

一、选择题(本大题共20个小题,每小题3分,共60分)

第Ⅱ卷(共 40 分)

二、填空题(本大题共5个小题,每小题3分,共15分)

21.

1

2

22.3 23.2 24 25.10

三、解答题(本大题共3个小题,共25分)

本大题的每小题给出一种(两种)解法,考生的其他解法,只要步骤合理,解答正

确,均应参照下述评分说明,给予相应的分数.

26.证明:在△ABC 中,因为E ,F 分别是棱AB ,AC 的中点,

所以EF ∥BC . ··············································································· 4分

又因为EF ?平面BCD , ···································································· 5分

BC ?平面BCD , ···································································· 6分

所以EF ∥平面BCD . ······································································· 8分

27.解:22()cos sin cos2f x x x x =-=. ························································· 2分

(1)()cos(2)cos 12126f πππ=?== ························································ 5分

(2)由2k π-π≤2x ≤2k k π∈Z ,

, 得2

k π

π-

≤x ≤k π,k ∈Z . ····························································· 7分 所以()f x 的单调递增区间为[2

k k ππ-π],,k ∈Z . ································· 8分 28.解:(1)因为函数()f x 有零点, 所以方程21

04

x ax ++

=有实数根. 所以21a ?-=≥0,解得a ≤1-,或a ≥1.

因此,所求a 的取值范围是a ≤1-,或a ≥1. ······································· 2分 (2)注意到1(0)04f =>,函数()f x 图象的对称轴为直线2

a

x =-. 解法一:

①若02

a

-…,即0a …时,

()f x 在区间(01),内没有零点. ·

························································· 3分

②若12

a -…,即2a -…时,

当5(1)04f a =+

<时,即5

4a <-,所以2a -…时,()f x 在区间(01),

内有1个零点; 当5(1)04f a =+…时,即5

4a -…,与2a -…矛盾,无解. ······················· 4分

③若012a

<-<时,即20a -<<时,

当221

()02424

a a a f -=

-+>,解得11a -<<. 所以10a -<<时,()f x 在区间(01),内没有零点. ·

······························· 5分 当221

()02424

a a a f -=

-+=,解得1a =±. 所以1a =-时,()f x 在区间(01),内有1个零点. ·

································· 6分 当221

()02424

a a a f -=

-+<,解得1a <-,或1a >. 若5

(1)04

f a =+

>, 得5

14

a -<<-,此时()f x 在区间(01),内有2个零点.

··························· 7分 若5(1)04f a =+…,

得5

24

a -<-…,此时()f x 在区间(01),内有1个零点. ·

························· 8分 综上,当1a >-时,()f x 在区间(01),内没有零点; 当1a =-,或5

4

a -…时,()f x 在区间(01),内有1个零点;

当514

a -<<-时,()f x 在区间(01),内有2个零点. ······························ 9分 解法二: ①当5(1)04f a =+

<时,即5

4

a <-时, ()f x 在区间(01),内有1个零点. ······················································· 3分

②当5(1)04f a =+

>时,即5

4a >-时, (ⅰ)若012

a

<-<时,即20a -<<时,

若221

()02424

a a a f -=

-+>,解得11a -<<. 所以当10a -<<时,()f x 在区间(01),内没有零点.

若221

()02424

a a a f -=

-+=,解得1a =±. 所以当1a =-时,()f x 在区间(01),内有1个零点.

若221

()02424

a a a f -=

-+<,解得1a <-,或1a >. 所以当514

a -<<-时,()f x 在区间(01),内有2个零点. ·

······················· 5分 (ⅱ)若12a -…,即2a -…时,与54a >-矛盾,无解. ·························· 6分

(ⅲ)若02a

-…,即0a …时,()f x 在区间(01),内没有零点. ·

··············· 7分 ③当5(1)04f a =+=时,即5

4

a =-时,

()f x 在区间(01),内有1个零点. ·

······················································ 8分 综上,当1a >-时,()f x 在区间(01),内没有零点; 当1a =-,或5

4

a -…时,()f x 在(01),内有1个零点;

当514

a -<<-时,()f x 在(01),内有2个零点. ·

··································· 9分

相关主题
文本预览
相关文档 最新文档