If and are in G.P

MATHEMATICS · Subjective · A Level · Mathematics · Sequences and series · Sequences and series

Problem

25. If

a, b, c

and

d

are in G.P. show that

\left(a^{2}+b^{2}+c^{2}\right)\left(b^{2}+c^{2}+d^{2}\right)=(a b+b c+c d)^{2}