how to perform FFT on this signal and frequency domain

t = (0:0.001:1); x = 110*sin(2*pi*50*t); y = 10*sin(2*pi*250*t); z=x+y; plot(z)

Answer 1

[Birdman]

Try this:

[pxx1,f1] = pwelch(y1,512,66.7,[],1000);
[pxx2,f2] = pwelch(y2,512,66.7,[],1000);
figure(1);
semilogx(f1,pxx1);xlabel('Frequency(Hz)');title('2*pi*50*t');
figure(2);
semilogx(f2,pxx2);xlabel('Frequency(Hz)');title('2*pi*250*t');

You will see each signal's frequency domain plot, which has peaks at 50 and 250 Hz respectively.

[zayaz aya]

do u have any simpler or different answer To use 'pwelch', the following product must be licensed, installed, and enabled: Signal Processing Toolbox :(

[zayaz aya]

im trying to download it

[Birdman]

Try this:

Fs = 1000;            % Sampling frequency                    
T = 1/Fs;             % Sampling period       
L = 1001;             % Length of signal
t = (0:L-1)*T;        % Time vector
y1=110*sin(2*pi*50*t);
y2=10*sin(2*pi*250*t);
f = Fs*(0:(L/2))/L;
Y1=abs(fft(y1));
Y2=abs(fft(y2))
figure(1);
semilogx(f,Y1(1:numel(f)));xlabel('Frequency(Hz)');title('2*pi*50*t');
figure(2);
semilogx(f,Y2(1:numel(f)));xlabel('Frequency(Hz)');title('2*pi*250*t');