Consider a discrete-time system that is characterized by the following difference equation:
Y(n) = x(n)cos?0n,
where ?0 is constant value, x(n)are the discrete-time input data of the system, y(n)are the discrete-time output data of the system.
Is the discrete-time system governed by the given difference equation:
(a) static or dynamic?
(b) time-invariant or time-variant?
(c) linear or nonlinear?
(d) causal or noncausal?
(e) stable or unstable?
Explain your answers for all questions and prove your conclusions analytically for questions b,c and d.