等比数列一道题目
问题描述:
等比数列一道题目
已知等比数列{an}中,a4a5=16,则log2a1+log2a2+...+log2a8=?
答
a4a5=a3a6=a2a7=a1a8=16
log2a1+log2a2+...+log2a8
=log2(a1a2a3a4a5a6a7a8)
=log2(16^4)
=log2(2^16)
=16