Online calculator which helps you in solving the expansion of a function in Fourier series.
Almost any function with the value of the period T (f(t)) may be a sum of cosines and sines from the arguments nwt (Fourier series), where n is a positive integer, t is time and w is equal to 2P/T is the angular frequency.
Each component of the Fourier series is called harmonic, any even function can be expanded in a Fourier series, which will consist of sines and cosines.
And the odd function can be expanded only in the ranks of the sinuses.