题目内容
若a<![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101230919273577507/SYS201311012309192735775002_ST/0.png)
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101230919273577507/SYS201311012309192735775002_ST/1.png)
A.
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101230919273577507/SYS201311012309192735775002_ST/2.png)
B.-
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101230919273577507/SYS201311012309192735775002_ST/3.png)
C.
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101230919273577507/SYS201311012309192735775002_ST/4.png)
D.-
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101230919273577507/SYS201311012309192735775002_ST/5.png)
【答案】分析:由a<
,知2a-1<0,故
=
=
.
解答:解:∵a<
,
∴2a-1<0,
∴
=
=
.
故选C.
点评:本题考查有理数指数幂的性质和应用,是基础题.解题时要认真审题,仔细解答.
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101230919273577507/SYS201311012309192735775002_DA/0.png)
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101230919273577507/SYS201311012309192735775002_DA/1.png)
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101230919273577507/SYS201311012309192735775002_DA/2.png)
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101230919273577507/SYS201311012309192735775002_DA/3.png)
解答:解:∵a<
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101230919273577507/SYS201311012309192735775002_DA/4.png)
∴2a-1<0,
∴
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101230919273577507/SYS201311012309192735775002_DA/5.png)
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101230919273577507/SYS201311012309192735775002_DA/6.png)
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101230919273577507/SYS201311012309192735775002_DA/7.png)
故选C.
点评:本题考查有理数指数幂的性质和应用,是基础题.解题时要认真审题,仔细解答.
![](http://thumb.zyjl.cn/images/loading.gif)
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若a<