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设数列{(-1)n-1•n}的前n项和为Sn,则S2009= .
设数列{(-1)n-1•n}的前n项和为Sn,则S2009= .
考点分析:
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已知{a
n}满足a
1=1,a
n+1=2a
n+1,则{a
n}通项为( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103101955580360911/SYS201311031019555803609009_ST/0.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103101955580360911/SYS201311031019555803609009_ST/1.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103101955580360911/SYS201311031019555803609009_ST/2.png)
D.
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满足|x|+|y|≤2的点(x,y)中整点(横纵坐标都是整数)有( )
A.9个
B.10个
C.13个
D.14个
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![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103101955580360911/SYS201311031019555803609007_ST/images0.png)
给出计算
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103101955580360911/SYS201311031019555803609007_ST/0.png)
的值的一个程序框图如图,其中判断框内应填入的条件是( )
A.i>10
B.i<10
C.i>20
D.i<20
查看答案
已知平面向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103101955580360911/SYS201311031019555803609006_ST/0.png)
=(1,2),
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103101955580360911/SYS201311031019555803609006_ST/1.png)
=(-2,m),且
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103101955580360911/SYS201311031019555803609006_ST/2.png)
,则
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103101955580360911/SYS201311031019555803609006_ST/3.png)
=( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103101955580360911/SYS201311031019555803609006_ST/4.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103101955580360911/SYS201311031019555803609006_ST/5.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103101955580360911/SYS201311031019555803609006_ST/6.png)
D.
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