fft amplitude and frequency

Started by g_arambatzis September 19, 2005
I am new in this group. I am trying to apply fft on my data but it
seems there is something that I don't understand. I searched previus
posts but nothing helped me.

Can anyboby help me to apply fft on this function,

f(x) = sin(2*x) + sin(3*x) + sin(4*x) , x in [0 , b]
b = 100 , 200 , 300

I have serious problems with the frequency domain as well as the
amplitude of the transformed signal.

Thanks a lot and please excuse my english.