[akj_]

i know this is kinda math related but always in my computer science problem question
how do you proof that n^2-2n+1 is big O of n^2
i started like this and i got stuck
let c = 1 and choose for all n>1

n^2-2n+1 <= n^2

i proofed the base step for n=2
an proceeded the inductive step where i got stucked

(n+1)^2-2(n+1)+1 <= (n+1)^2