题目内容
设
=(2cos
,1),
=(cos
,
sin2
),
=
·
,![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335665266.png)
R.
⑴若
=0且![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335665266.png)
[
,
],求
的值;
⑵若函数
=
(
)与
的最小正周期相同,且
的图象过点(
,2),求函数
的值域及单调递增区间.
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335665296.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335665266.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335696311.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335665266.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335727341.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335665266.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335759447.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335665296.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335696311.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335665266.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335837246.png)
⑴若
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335759447.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335665266.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335868242.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335899256.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335915423.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335665266.png)
⑵若函数
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335946442.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335993893.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336024639.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335759447.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335946442.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336071421.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335946442.png)
(1)
;(2)
的值域为
,单调递增区间为
.
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336102521.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335946442.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336133425.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/201408240253361641101.png)
试题分析:(1)首先利用平面向量的坐标运算及和差倍半的三角函数公式,
将
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335759447.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335759447.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336211898.png)
根据
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336211898.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335665266.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335868242.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335899256.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335915423.png)
(2)首先确定得到
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335946442.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336414837.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336429957.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335946442.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336133425.png)
单调递增区间为
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/201408240253361641101.png)
试题解析:(1)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335759447.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335665296.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335696311.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336539825.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336554164.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336570809.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336211898.png)
由
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336601520.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336211898.png)
∴
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336632904.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335665266.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335868242.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335899256.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335915423.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336710984.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336726727.png)
∴
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336102521.png)
(2)由(1)知
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336773395.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336788629.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/201408240253368041179.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336819364.png)
∴
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335946442.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336414837.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336429957.png)
∴
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025335946442.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025336133425.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/201408240253361641101.png)
![](http://thumb.zyjl.cn/images/loading.gif)
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