1. The problem statement, all variables and given/known data Prove that the system is either T.I. or is not T.I. 2. Relevant equations y(n) = x(n)*h(n) x(n) is the input signal y(n) is the output signal h(n) is the system 3. The attempt at a solution Inputing x(n-n0) into the system I get out: as the output x(n-n0)*h(n) Since y(n-n0) = x(n-n0)*h(n-n0) != x(n-n0)*h(n) the system is not T.I. I think I am doing this wrong.