To analyze the periodic properties of F(t) it is useful to uncover
a functional representation of the signal in terms of the
orthogonal functions 
and 
of period L.
To determine the Fourier series for F(t) we must
find the constants 
and 
so that the following identity holds [27]:
Fourier showed that the constants and in equation (3.63)
are computed from F(t) by means of the
integral formulas
and
