So if we were talking about a Fourier Series, would this be the basis for the Hilbert space:
{0.5, cos x, sin x, cos 2x, sin 2x, cos 3x, sin 3x, cos 4x, sin 4x, ... }
and this be the vector that represents the function?:
{a0, a1, b1, a2, b2, a3, b3, a4, b4, a5, b5, a6, b6, ...}
If...