I have the Fourier-series for the function:
f(x) = x for -Pi < x < Pi.
I know wish to find the Fourier-series for the function:
g(x) = x for -p < x < p,
where p is a random period.
The Attempt at a Solution
Ok, the obvious thing here is to use the result from f(x). If thought that if I define f(p*x/Pi) = g(x) = f(y), then I just insert x=y*Pi/p. But in the result of this exercise, they have an additional p/Pi in front of the sum. Where does this come from?