An LTI system is described by the difference equation y[n] = bx[n] 0.81y[n 2]. (a) Determine the frequency response H(ej) of the system in terms of b. (b) Determine b so that |H(ej)|max = 1. Plot the resulting magnitude response. (c) Graph the wrapped and the unwrapped phase responses in one plot. (d) Determine analytically the response y[n] to the input x[n] = 2 cos(0.5n + 60 ). (e) Using MATLAB compute the steady-state response to x[n] above and verify your result.