Prove that
Thanks a lot .
let prove it by induction okay
let
first see if n=1 and 2 true
and
at 1 the statement is true try when n=2
you will find it is true now suppose that n is true try n+1
......(*)
you begin with the RHS in (*) and finished with LHS in the (*) formula
so P_{n+1} is true the proof end