The -order Fourier series of is by default defined to be with. The multidimensional Fourier series of is given by with. The following options can be given. Convergenza Serie di Fourier. Fourier Transform, Fourier Series, and frequency spectrum - Duration.
Active4 years, 5 months ago
$begingroup$
This is my first step with Fourier series and I'm stuck at the beginning. So my solution:
The function $f(x)=cos^2x$ is an even function. Thus I use formulas:
$a_0 = frac{2}{pi} int _0 ^pi cos^2x,text dx$ (1)
$a_n = frac{2}{pi}int _0^pi cos^2x cos nx,text dx$ (2)