已知數列{an}是等比數列,m,n,p∈N*,且m,n,p成等差數列,求證:am,an,ap依次

已知數列{an}是等比數列,m,n,p∈N*,且m,n,p成等差數列,求證:am,an,ap依次

2n = m + p
am * q / a1 = q^m
an * q / a1 = q^n
ap * q / a1 = q^p
q^m * q^p = q^n * q^n
am * ap = an ^ 2