Kontrollküsimused 3. osa kohta – Signaalitöötluse põhivara

Which of the following signals are periodic?

Which signal is shown on the figure?

2*sin(2*t+Pi/2)

cos(2*t-Pi/2)

2*cos(t-Pi/2)

2*cos(t+Pi/2)

sin(2*t-Pi/2)

Consider these signals:

1.

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2.

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3.

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4.

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5.

Match the equations with the corresponding signals!

Signal #1	e^jwt Unselect cos(t) Unselect e^wt Unselect u[n+2] Unselect delta[n-3] Unselect
Signal #2	e^jwt Unselect cos(t) Unselect e^wt Unselect u[n+2] Unselect delta[n-3] Unselect
Signal #3	e^jwt Unselect cos(t) Unselect e^wt Unselect u[n+2] Unselect delta[n-3] Unselect
Signal #4	e^jwt Unselect cos(t) Unselect e^wt Unselect u[n+2] Unselect delta[n-3] Unselect
Signal #5	e^jwt Unselect cos(t) Unselect e^wt Unselect u[n+2] Unselect delta[n-3] Unselect

A discrete time signal is shown on the figure below. What is the formula of the signal?

u[4]-u[2]

u[n-2]-u[n+4]

u[2-n]-u[n-4]

u[n+2]-u[n-4]

A system is described with y(t)=x(t)*cos(w*t), where x(t) is the input of the system. Is the system linear?

True

False

Is the sum of two periodic signals also always periodic?

True

False

According to Euler formula equals to ...