(d) Suppose the sound from the engine of a car is modelled by the function
x(t) = cos[\omega(t + \tau) + \theta] where \tau is a time delay, and \theta is a phase.
Find the frequency (in Hz) and period (in seconds) of the signal x(t) when:
(i) [\omega, \tau, \theta] = [\pi/3, 1/2, \pi/2]
(ii) [\omega, \tau, \theta] = [3\pi/4, 1/2, \pi/4].
[2 marks]
[2 marks]
(e) Suppose the signal from the braking activities of a car is modelled as:
x(t) = 3e^{-2t}u(t).
[5 marks]
Sketch this signal and find the energy and power of the signal.
(f) The relationship between the input and output of a discrete time system is
given by the expression:
y[n]+2y[n-1] = x[n]+2x[n-2], where x[n] is the input and y[n] is the output
of the system.
(i) Sketch the block diagram representation of the system.
[2 marks]