等比数列:a6=6,a9=9, 则a3=?
问题描述:
等比数列:a6=6,a9=9, 则a3=?
答
a9=a6*d*d*d
d^3=3/2
a6=a3*d^3
a3=a6/d^3=6/(3/2)
=4