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高三数学(文科)答案第 1 页 共 6 页
二○一七届高三模拟考试
数学(文科)参考答案及评分标准 2017.3
一、选择题:本大题共 10小题,每小题 5分,共 50分.
BDAC CBAD AC
二、填空题:本大题共 5小题,每小题 5分,共 25分.
11.相交 12. 2 13. 1 14. 1{ |
e
λ λ = − ,或 0}λ� 15. 2 3
三、解答题:本大题共 6小题,共 75分.
16. 解:(1)分数在[50, 60)的频率为0.008 10 0.08× = . ········································· 2分
由茎叶图知,分数在[50, 60)内的频数为 2,所以全班人数为
2 25
0.08
= . ······ 4分
分数在[80,90)内的频数为 25 22 3− = . ······························································· 6分
(2)将分数在[80,90)内的 3份试卷记为 1 2 3, ,a a a ,分数在[90,100)内的 2份试卷记为
1 2,b b ,在[80,100)之间的试卷中任取两份的基本事件为: 1 2( , )a a , 1 3( , )a a , 1 1( , )a b ,
1 2( , )a b , 2 3( , )a a , 2 1( , )a b , 2 2( , )a b , 3 1( , )a b , 3 2( , )a b , 1 2( , )b b ,共10个. ···· 10分
其中,至少有一份试卷的分数在[90,100)内的基本事件有7个. ·······················11分
故至少有一份试卷的分数在[90,100)内的概率是
7
10
. ····································· 12分
注:第(2)问中,无论按有序,还是按无序,只要计算正确,均给分.
17.解(1)由题意,
π( ) sin(2 ).
3
f x x= − ····································································· 2分
令
π π2 π
3 2
x k− = + , .k ∈ Z ··············································································· 4分
解得 ( )y f x= 图象的对称轴方程 π 5π
2 12
kx = + , .k ∈ Z ····································· 6分
(2)由
3( )
2
f A = ,得 πsin(2 )
3
3 .
2
A − =
由0 πA< < ,得 π π 5π2 ( , ).
3 3 3
A − ∈ − ·································································· 7分
所以
π π2
3 3
A − = ,或 π 2π2 .
3 3
A − = 所以 π
3
A = ,或 π .
2
A = ······························· 9分
由正弦定理,得
sin sin
b a
B A
= ,所以
sinsin .b AB
a
=
高三数学(文科)答案第 2 页 共 6 页
O
A
B C
D
A1
B1 C1
D1
当
π
3
A = 时,
2 3 3
sin 13 2sin
2 2
b AB
a
×
= = = ; ················································· 10分
当
π
2
A = 时,
2 3 1sin 33sin .
2 3
b AB
a
×
= = = ·······················································11分
综上, sin B的值为 1
2
,或
3 .
3
············································································ 12分
18.证明:(1)在四棱台 1 1 1 1ABCD A B C D− 中,连接 1 1A C .