User talk:142.120.58.116

I want to edit the Fourier series page
I believe the first equation on the page: $$\Chi_f(\tau) \triangleq \int_{P} s(x)\cdot \cos\left( 2\pi f (x-\tau) \right)\, dx
 * \quad \tau \in \left[ 0,\ 2\pi / f \right]$$

has an error. The valid interval for $$\tau$$ is $$\left[ 0, 1 / f \right]$$ (alternatively $$\left[ 0, P \right]$$). The equation can also be rewritten as:

$$\Chi_f(\tau) \triangleq \int_{P} s(x)\cdot \cos\left( 2\pi f x-\tau \right)\, dx
 * \quad \tau \in \left[ 0,\ 2\pi / f \right]$$

to keep the original interval for $$\tau$$.