题目内容
已知函数
;
(1)写出函数
的单调递增区间;
(2)若![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948514275.png)
求函数
的最值及对应的
的值;
(3)若不等式
在![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948514275.png)
恒成立,求实数
的取值范围.
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/201408232129484671036.png)
(1)写出函数
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948498493.png)
(2)若
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948514275.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948530689.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948545510.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948514275.png)
(3)若不等式
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948576697.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948514275.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948530689.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948623339.png)
(1)[
;(2)
时,
,
时,
;(1)(-1,
).
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948701999.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948795522.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948810653.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948873524.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948904750.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948920337.png)
本试题主要考查了三角函数的性质的运用。
解:(1)由
得:
, 所以
(x) 的单调递增区间为[
。(6分)
(2)由(1)知
,
x
,所以
故 当
时,即
时,
(8分)
当
时,即
时,
(10分)
(3)解法1
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948576697.png)
(x
);
且
故m的范围为(-1,
)。 (14分)
解:(1)由
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/201408232129489661083.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212949029897.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212949044517.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212949060318.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948701999.png)
(2)由(1)知
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/201408232129491691029.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212949185222.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948530689.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212949232876.png)
故 当
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212949263677.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948795522.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948810653.png)
当
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212949325729.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948873524.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948904750.png)
(3)解法1
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212949185222.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948576697.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212949606825.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948530689.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212949700794.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212949715751.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823212948920337.png)
![](http://thumb.zyjl.cn/images/loading.gif)
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