function Ex_4
Ts=0.001;
t=0:Ts:5;
f1=70;
f2=200;
f3=300;
x1=sin(2*pi*f1*t);
x2=sin(2*pi*f2*t);
x3=sin(2*pi*f3*t);
x=x1+x2+x3;
Fs=1000;
freq=0:Fs-1;
freq_domain=fft(x,Fs);
freq_domain_abs=abs(freq_domain);
figure
stem(freq,freq_domain_abs)