Question
If a, b, c are in GP., prove that a2 + b2, ab + bc, b2 + c2 are also in GP.
Solution
Here, a, b, c are in G.P. Let r be common ratio of G.P.
∴ b = ar, c = ar2,
Now, will be in G.P.
if or if
or if or if r = r which is true.
Hence, if a, b, c are in G.P. then are also in G.P.