I have just started out learning the basics of discrete time. I would like some help to understand if cos2n is periodic or not. I know the discrete time formula for periodicity: x[n] = x[n+N]. I Also know that ω=2πf, ω=2π/Ν.
I searched the web and i found a solution that goes like so: x [ n + N ] = C o s ( 2 n + 2 N ) therefore 2 N = Ω = m 2π, m ∈ Z, (at quora.com). I do not really understand it, i think that m integer does not fit in the standard formula i know of: ω=2πf. Can you solve it using a step by step guide for 'dummies'?