y(n)=x(4n+1). Is this system T.I or NOT T.I
The professor marked this question wrong for my homework. He says it's NOT time invariant. I proved it is time invariant.
System is time invariant if a shift in time in input results in the same shift in time when the output is shifted.
The Attempt at a Solution
shift in the x:
y2=shift in y=y(n-n0)=x(4(n-n0)+1)
They are the same, therefore they system is time invariant.
The professor marked this problem wrong for me, and he gave me the run-around when I asked for him to prove it. Did I do this right?