√2/8是等差数列,4√2,4,2√2,…的第n项,则n值为
问题描述:
√2/8是等差数列,4√2,4,2√2,…的第n项,则n值为
答
4√2,4,2√2
转化为√32 √16 √8
an=√32/2^(n-1)
√32/2^(n-1)=√2/8
=√32/32
2^(n-1)
=32
求出n=6