How to i produce a signal which is a combination of three sinusoidal signal oscillate a frequency?

sinusoidal signals oscillate at frequency of 10hz, 100hz, and 200hz (random amplitude and phase). Show and explain the generated sinusoidal waveform, its frequency spectrum and its phase by using function subplot.

Answer 1

[Fabio Freschi]

% frequencies
f = [10 100 200];

% random amplitudes
V = rand(3,1);

% random phase
phi = 2*pi*rand(3,1);

% time axis
nT = 3;  % number of periods
t = linspace(0,nT/min(f),nT*200);

% the signal
v = V(1)*sin(2*pi*f(1)*t+phi(1))+V(2)*sin(2*pi*f(2)*t+phi(2))+V(3)*sin(2*pi*f(3)*t+phi(3));

% plot
figure,
plot(t,v);