题目内容
(12分)已知定义域为
的单调函数
且
图关于点
对称,当
时,
.
(1)求
的解析式;
(2)若对任意的
,不等式
恒成立,求实数
的取值范围.
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233637755303.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233637771496.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233637802498.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233637849431.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233637864393.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233637880743.png)
(1)求
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233637771496.png)
(2)若对任意的
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233637927408.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233637958948.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233637973306.png)
(1)
;(2)
。
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/201408232336380051405.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638020489.png)
本试题主要是考查了函数的奇偶性以及函数的单调性的运用。
(1)定义域为
的函数
是奇函数
当
时,
又
函数
是奇函数
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638239744.png)
(2)
且
在
上单调
在
上单调递减,化简表达式得到求解。
解:(1)
定义域为
的函数
是奇函数
----2分 当
时,
又
函数
是奇函数
-5分
综上所述
----6分
(2)
且
在
上单调
在
上单调递减 --8分由
得![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233639034849.png)
是奇函数
,又![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638176235.png)
是减函数 ![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233639143195.png)
-----10分
即
对任意
恒成立
得
即为所求 -------12分
(1)定义域为
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638051316.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233637771496.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638098570.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638114386.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638129409.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638145764.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638176235.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233637771496.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638223759.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638239744.png)
(2)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638270905.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233637771496.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638051316.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638332501.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638051316.png)
解:(1)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638176235.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638051316.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233637771496.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638098570.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638114386.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638129409.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638145764.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638176235.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233637771496.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638223759.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638239744.png)
综上所述
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/201408232336380051405.png)
(2)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638270905.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233637771496.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638051316.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638332501.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638051316.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233639019910.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233639034849.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233639065490.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233639081836.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638176235.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233639112447.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233639143195.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233639159631.png)
即
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233639190664.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233637927408.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233639221690.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233638020489.png)
![](http://thumb.zyjl.cn/images/loading.gif)
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