【题文】函数在上为增函数,则实数道的取值范围是__________.
【题文】函数在上为增函数,则实数道的取值范围是__________.
题型:难度:来源:
【题文】函数
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101707-84494.png)
在
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101708-22076.png)
上为增函数,则实数
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101708-55588.png)
道的取值范围是__________.
答案
【答案】
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101708-93865.png)
解析
【解析】
试题分析:设
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101709-42348.png)
,则
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101709-86374.png)
开口向上,对称轴为
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101709-58103.png)
,则原题实际等价于
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101709-37840.png)
,即所求的
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101708-55588.png)
取值范围是
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101708-93865.png)
.
考点:对数函数和二次函数复合的问题应用.
举一反三
【题文】已知函数
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101559-57906.png)
;
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101559-93699.png)
(1)若
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101600-33120.png)
的定义域为
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101600-30049.png)
,求实数
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101600-63581.png)
的取值范围.
(2)若
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101600-33120.png)
的值域为
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101600-30049.png)
,则实数
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101600-63581.png)
的取值范围.
(3)求函数
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101600-52790.png)
的递减区间.
【题文】已知函数
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101548-80887.png)
;
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101548-51108.png)
(1)若
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101549-69020.png)
的定义域为
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101549-14439.png)
,求实数
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101550-22946.png)
的取值范围.
(2)若
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101549-69020.png)
的值域为
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101549-14439.png)
,则实数
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101550-22946.png)
的取值范围.
(3)求函数
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101550-85449.png)
的递减区间.
【题文】下列四组中的函数
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101543-80254.png)
与
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101543-71347.png)
,是同一函数的是( )
【题文】下列四组中的函数
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101537-73791.png)
与
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330101537-94613.png)
,是同一函数的是( )
最新试题
热门考点