Beginning in the late 1940s, many guitar amplifiers incorporated a tremolo circuit that varied the volume3 of the amp over time. Suppose that the input/output relationship of this circuit could be modeled as y(t) = [A sin(Bt) + C]x(t), where x(t) is the input and y(t) is the output. This is a substantial simplification of the behavior of an actual tremolo circuit, but we’ll call it close enough for now. For each part, briefly explain your reasoning.

(a) Specify all combinations of A, B, and C that will cause this system to be time-invariant
(b) Specify all combinations of A, B, and C that will cause this system to be linear