已知等比数列{an}满足an>0,n=1,2,…,且a5·a2n-5=22n(n≥3),则当n≥1时,log2a1+log2a3+…+log2a2n-1=().A.n(2n-1)B.(n+1)2

题目简介

已知等比数列{an}满足an>0,n=1,2,…,且a5·a2n-5=22n(n≥3),则当n≥1时,log2a1+log2a3+…+log2a2n-1=().A.n(2n-1)B.(n+1)2

题目详情

已知等比数列{an}满足an>0,n=1,2,…,且a5·a2n-5=22n(n≥3),则当n≥1时,log2a1+log2a3+…+log2a2n-1=(  ).
A.n(2n-1)B.(n+1)2C.n2D.(n-1)2
题型:单选题难度:中档来源:不详

答案

C
log2a1+log2a3+…+log2a2n-1=log2(a1a3…a2n-1)=log2(aa2n-5)n2.

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