Fourie sequence

%%Time specifications:
   Fs = 120;                      % samples per second
   dt = 1/Fs;                     % seconds per sample
   StopTime = 1;                  % seconds
   t = (0:dt:StopTime-dt)';
   N = size(t,1);
   %%Sine wave:
   Fc1 = 40;
   Fc2 = 120;                       % hertz
   x = 2*cos(2*pi*Fc1*t) + sin(2*pi*Fc2*t) ;
   %%Fourier Transform:
   X = fftshift(fft(x));
   %%Frequency specifications:
   dF = Fs/N;                      % hertz
   f = -Fs/2:dF:Fs/2-dF;           % hertz
   %%Plot the spectrum:
   figure;
   plot(f,abs(X)/N);
   xlabel('Frequency (in hertz)');
   title('Magnitude Response');