Función IMPAR f(x) con periodo p=2L

$${\displaystyle f(x)=\sum _{n=1}^{\infty }b_{n}\sin {\frac {n\pi x}{L}}}$$

$$a_{0}=0$$

$$a_{n}=0$$

$$b_{n}={\frac {2}{L}}\int _{0}^{L}f(x)\sin {\frac {n\pi x}{L}}dx$$