【题文】已知,则满足不等式的实数的最小值是 .
题型:难度:来源:
答案
【答案】1
解析
【解析】
试题分析:∵lga+lgb=0,∴ab=1,且a、b都为正数.由于
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103252-80533.png)
,当且仅当a=1时,等号成立.同理可得
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103253-60288.png)
,∴
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103253-29008.png)
.不等式
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103253-92023.png)
的实数λ的范围是λ≥1,故答案为1.
考点:基本不等式.
举一反三
【题文】已知
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103235-97336.png)
为正实数,且满足
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103235-70781.png)
,则使
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103236-93668.png)
恒成立的
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103236-93134.png)
的取值范围为_________.
【题文】已知函数
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103206-94134.png)
,则
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103206-33011.png)
的值为
【题文】定义在
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103145-47051.png)
上的函数
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103146-27059.png)
满足
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103146-39405.png)
,则
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103146-31545.png)
的值为_____.[
【题文】设
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103140-66111.png)
,则( )
【题文】已知函数
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103119-44294.png)
,若
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103119-91544.png)
,
且
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103120-87593.png)
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103120-21691.png)
,则
![](http://img.shitiku.com.cn/uploads/allimg/20200330/20200330103120-25682.png)
( )
A.2 | B.4 | C.8 | D.随 值变化 |
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