How to Show that the Fourier Series of 1-x, infinite sum of $\frac{2}{(n\pi)} \sin(n \pi x)$ equals 1 at x=0?

Question

I am confused how the Fourier sine series for 1-x, which is

$\sum_{n=1}^\infty \frac{2}{(n\pi)} \sin(n \pi x)$

equals $1$ at $x=0$.

Thanks!