14.40 Observe that Eq. (14.28) can be used to find the frequencies in the passband at which | T | is at its peaks and at its valleys. (The peaks are reached when the cos2[ ] term is zero, and the valleys correspond to the cos2[ ] term equal to unity.) Find these frequencies for a fifth-order filter.
Peaks: 0.95ωp, 0.59ωp, 0; Valleys: ωp, 0.81ωp, 0.31ωp