shuasini006
幼苗
共回答了15个问题采纳率:86.7% 举报
已知函数
![](https://img.yulucn.com/upload/1/35/13538c0d2e7aa31dfcb3a20af9f425c4_thumb.jpg)
.
(1)若
![](https://img.yulucn.com/upload/f/03/f03c322fa6d3fd45baf03da9acf435a3_thumb.jpg)
在
![](https://img.yulucn.com/upload/a/6f/a6fe4a416fd5f56ef32b9d0d37b4f942_thumb.jpg)
处取得极大值,求实数
![](https://img.yulucn.com/upload/6/c5/6c5abae1b6a277b60cb43c95489b8b52_thumb.jpg)
的值;
(2)若
![](https://img.yulucn.com/upload/f/9c/f9ce392ef29d1bcc863acc4d75b34ea8_thumb.jpg)
,求
![](https://img.yulucn.com/upload/f/03/f03c322fa6d3fd45baf03da9acf435a3_thumb.jpg)
在区间
![](https://img.yulucn.com/upload/d/8b/d8bea8c0c55916acd8e3babea51a8eb2_thumb.jpg)
上的最大值.
(1)
![](https://img.yulucn.com/upload/7/c0/7c0bb246ad56be9eced5274fac192b81_thumb.jpg)
;(2)详见解析.
试题分析:(1) 本小题首先利用导数的公式和法则求得原函数的导函数,通过列表分析其单调性,进而寻找极大值点;(2) 本小题结合(1)中的分析可知参数
![](https://img.yulucn.com/upload/6/c5/6c5abae1b6a277b60cb43c95489b8b52_thumb.jpg)
的取值范围影响函数在区间
![](https://img.yulucn.com/upload/d/8b/d8bea8c0c55916acd8e3babea51a8eb2_thumb.jpg)
上的单调性,于是对参数
![](https://img.yulucn.com/upload/6/c5/6c5abae1b6a277b60cb43c95489b8b52_thumb.jpg)
的取值范围进行分段讨论,从而求得函数在区间
![](https://img.yulucn.com/upload/d/8b/d8bea8c0c55916acd8e3babea51a8eb2_thumb.jpg)
上的单调性,进而求得该区间上的最大值.
试题解析:(1)因为
令
![](https://img.yulucn.com/upload/6/5c/65c601cd4ed934953da5a8e6f26e403b_thumb.jpg)
,得
![](https://img.yulucn.com/upload/7/81/78198d78b5aa01ca5ed83982ccd72cac_thumb.jpg)
,
所以
![](https://img.yulucn.com/upload/9/28/928e2f17be25b653755b716e4acefb9e_thumb.jpg)
,
![](https://img.yulucn.com/upload/a/1f/a1f450e76be840169d58fd027e59dae1_thumb.jpg)
随
![](https://img.yulucn.com/upload/f/5f/f5fd095f6e6664b6f6dd3af28e779c3f_thumb.jpg)
的变化情况如下表:
0
0
↗
极大值
↘
极小值
↗
所以
![](https://img.yulucn.com/upload/7/c0/7c0bb246ad56be9eced5274fac192b81_thumb.jpg)
&n
1年前
8