I don't think so. The question looks very simple and your answer looks logical. But if you try to use a simple input say unit step(x(n)=u(n)) the two answers differ(the one got through convolution and one by direct substitution).correct?
Its time invariant but certainly non-linear.Is this in line with what the rest think?
Thank you for the clear steps shown (missed out on scaling property though nevertheless proves the point it is non-linear)Its time invariant but certainly non-linear.
let x1(n) =1 then output y1(n)=1+c
let x2(n) =2 then output y2(n)=2+c
let x(3)=x1(n)+x2(n)=3 then y3(n)=3+c
but y1(n)+y2(n)=3+2c which is not equal to y3(n) hence its non-linear.
It was not missed. It was intentionally left out. Its only needed if you can't prove non-linearity via the simple additive property.missed out on scaling property
There is nothing called nonlinear impulse response. I think it requires state diagram analysis.nonlinear impulse response