若數(shù)列{an}滿足a1=2且an+an-1=2n+2n-1,Sn為數(shù)列{an}的前n項和,則log2(S2012+2)等于( ?。?A.2013 B.2012 C.2011 D.2010
若數(shù)列{an}滿足a1=2且an+an-1=2n+2n-1,Sn為數(shù)列{an}的前n項和,則log2(S2012+2)等于( ?。?br/>A. 2013
B. 2012
C. 2011
D. 2010
數(shù)學人氣:654 ℃時間:2020-05-13 01:43:51
優(yōu)質解答
∵a
n+a
n-1=2
n+2
n-1,
∴a
n=2
n,即數(shù)列{a
n}是公比q=2的等比數(shù)列,
則S
n=
=2
n+1-2,
則S
2012=2
2013-2,
則log
2(S
2012+2)=log
22
2013=2013,
故選:A.
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