The pole-zero diagram for a certain digital filter is shown below:
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(a) Write the corresponding z-domain transfer function H(z) for this filter (assume that there is no additional gain constant - the poles and zeros depict H(z) completely).
(b) This filter is driven by a sum of signals x[n], where
x[n] = 3 u[n] + 2 (-1)^n u[n].
Write the mathematical form of the filter's steady-state output waveform y[n] in response to x[n] after the filter's transient response has decayed away.
Hint: To what points on the unit circle in the z-plane does each term of x[n] correspond in terms of frequency ω? This is fundamentally a frequency response calculation - if you're doing elaborate transforms and inverse transforms, you're missing the simplicity of this problem! Use graphical analysis of the pole-zero map to speed the response computation.