Half-Period Fourier Series
In modeling some physical problems we may only need to consider a function f(x)
that is defined on [0, L]. We do not need f to be periodic, because we are only
interested in x values from 0 to L. In order to calculate a Fourier series,
however, we need to extend the function to
[-L, L]. This can be done using even or odd periodic extensions, as described
earlier (review this section now, if necessary).
Up to Fourier Series via Sturm-Liouville Equations
Fourier Sine Series