题目内容
(本小题满分12分)
已知函数
其中![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824004219617440.png)
(1)、若
的单调增区间是(0.1),求m的值
(2)、当![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824004219663332.png)
时,函数
的图像上任意一点的切线斜率恒大于3m,求m的取值范围.
已知函数
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/201408240042196011181.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824004219617440.png)
(1)、若
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824004219648447.png)
(2)、当
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824004219663332.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824004219679326.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824004219695562.png)
(1) m="-2" ;(2)(-1,0)
试题分析:(1)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/201408240042197101407.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/201408240042197261356.png)
因为
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824004219648447.png)
则
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/201408240042197571268.png)
所以
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/201408240042197731493.png)
解得m=-2 (4分)
(2)、设
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824004219804723.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824004219913775.png)
切线斜率K=
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/201408240042199291381.png)
即
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/201408240042199441013.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824004219975529.png)
令
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/201408240042201161595.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824004220131743.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/201408240042201471093.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824004220163760.png)
ⅰ当
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824004220194568.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824004220209525.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/201408240042202251242.png)
ⅱ当
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824004220241612.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824004220272419.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/201408240042203031152.png)
此时无解。 (10分)
综上所述:
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824004220428337.png)
点评:导数的应用是高考的一个重点,考查了分类讨论思想,要注意分类讨论时做到不重不漏
![](http://thumb.zyjl.cn/images/loading.gif)
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