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高中数学试题 >
设Sn是等差数列{an}的前n项和,若则=( ) A. B. C. D.
设S
n是等差数列{a
n}的前n项和,若
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103095909743810735/SYS201311030959097438107002_ST/0.png)
则
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103095909743810735/SYS201311030959097438107002_ST/1.png)
=( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103095909743810735/SYS201311030959097438107002_ST/2.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103095909743810735/SYS201311030959097438107002_ST/3.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103095909743810735/SYS201311030959097438107002_ST/4.png)
D.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103095909743810735/SYS201311030959097438107002_ST/5.png)
考点分析:
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