等比数列:a6=6,a9=9, 则a3=?

问题描述:

等比数列:a6=6,a9=9, 则a3=?

a9=a6*d*d*d
d^3=3/2
a6=a3*d^3
a3=a6/d^3=6/(3/2)
=4