Question-76
Let fn be the nth Fibonacci number. Prove that 
when n is a positive integer.
Solution
The basis step (n = 1) is clear, since 
= 1 . Assume the inductive hypothesis. Then 
as desired.
= fnfn +1 + 
= fn+1(fn + fn+1)
=fn + 1 fn + 2 ,
The basis step (n = 1) is clear , since $f_{1}^{2 = f1f2 = 1. Assume the inducive