Consider a desired causal impulse response hd [n] that we wish to approximate by a system having impulse response h[n] and system function

(a) Suppose a is given, and we wish to determine the unknown parameter b which minimizes E. Assume that |a|
(b) Suppose b is given, and we wish to determine the unknown parameter a which minimizes E. Is this a nonlinear problem? If so, show why. If not, determine a