4. a. Determine the Nyquist sampling rate for the signal sinc(100πt)+3sinc² (60πt). [10 marks] b. Explain the concept of an anti-aliasing filter. [5 marks] c. Using the z-transform, find the output y[k] of an Linear time-invariant discrete system specified by the equation 2yk 2 3yk+1]+y[k] = 4f[k + 2] - 3f[k+1] if the initial conditions are y[-1] = 0, y[-2] = 1 and the input f[k] = (4)-ku[k]. [10 marks]

Fig: 1