\[f(x)=\dfrac{a_0}{2}+\displaystyle\sum_{n=1}^\infty \left[a_n cos\left(\dfrac{2n\pi}{T}x\right)+b_n sen\left(\dfrac{2n\pi}{T}x\right)\right] \]\

\[a_0=\dfrac{2}{T}\displaystyle\int_{0}^{T}f(x)\,dx\]\

\[a_n=\dfrac{2}{T}\displaystyle\int_{0}^{T}f(x)cos\left(\dfrac{2n\pi}{T}x\right)dx\]\

\[b_n=\dfrac{2}{T}\displaystyle\int_{0}^{T}f(x)sen\left(\dfrac{2n\pi}{T}x\right)dx\]