Consider a finite impulse response (FIR) filter H : [Z R] [Z R] having impulse response h and frequency response H. Part (a) below discloses several pieces of information about the filter H. Your task in that part is to determine the impulse response h completely. In the subsequent parts you explore the filter H of part (a) further. Suppose you're given the following pieces of information about the filter H: (I) H is a causal filter. (II) There exists a filter A : [Z R] [Z R] having impulse response a and frequency response A, about which we know the following: (i) R, A(ej) = H(ej) ei2