In: Advanced Math
Which statement is false about the DTFT of a sequence x(n)?
(a) It always exists (b) It is continuous in w (c) It is periodic (d) It can be complex
The principle that there can be no output before there is any input to a system is called
(a) linearity (b) shift invariance (c) relativity (d) causality
Is the transform T[x(n)] =x2(n) linear? Justify your answer using sequences x1(n)=δ(n-0) and x2(n)=δ(n-1) with a = 1 and b = -2.