3.25 filter specifications. an analog signal, bandlimited to 20 hz is corrupted by high-frequency noise. the spectrum of the noise is from 25 hz to 35 hz. the noisy analog signal is sampled at 60 hz. a digital lowpass filter is to be designed so as to remove the noise from the signal. what would you choose for the desired frequency response d(ω) and weighting function w(ω)? sketch those functions for 0 ≤ ω ≤ π where ω is normalized frequency (radians/sample).