2.4. Given the following FIR filter impulse responses what are their H(z) and H(z-1)? What are the zeros of the filters? Express the transfer functions in terms of zeros and poles? Prove that these filters have linear phases.

a. h[n] = {0.5, 0.5}

b. h[n] = {0.5, 0.0, -0.5}

c. h[n] = {0.5, 0.0, 0.5}

d. h[n] = {0.25, -0.5, 0.25}