State with reason if the following signals are periodic If p

State with reason if the following signals are periodic. If periodic, determine the period. e^j k/5 cos(0.1 pi k + 1.2) cos(0.3 pi k + pi/4) + 2sin(0.2 pi k)

Solution

(a) f = 1/5

period N = 5

(b) f = w/2*pi

=0.1 pi / 2 pi

= 1/20

period N = 20

(c) f₁ = w/2 pi

= 0.3 pi / 2 pi

= 3/20

f₂ = w/2 pi

= 0.2 pi/2 pi

= 2/20

so, the period N is 20