Compute the DTFT of the following discrete-time signals. Use Euler's formula for trigonometric functions, and consider the DTFT properties and commonly encountered summations.

 

 

Transcribed Image Text:

(a) x[n] = (0.8)" u[n] (b) x[n] (0.5)" cos (4n)u[n] (c) x[n] = n(0.5)" u[n] (d) x[n] = n(0.5)" cos(4n)u[n] (e) x[n] = 5(0.8) cos(2n)u[n] (f) x[n] = (0.5) -00<n<∞0 (g) x[n] = (0.5) cos(4n) →∞<n<∞ (a) x[n] = (0.8)" u[n] (b) x[n] (0.5)" cos (4n)u[n] (c) x[n] = n(0.5)" u[n] (d) x[n] = n(0.5)" cos(4n)u[n] (e) x[n] = 5(0.8) cos(2n)u[n] (f) x[n] = (0.5) -00<n<∞0 (g) x[n] = (0.5) cos(4n) →∞<n<∞