!$ 1 + \displaystyle \sum_{n=1}^\infty {\begin{Bmatrix} { \large 2 \over ( n \pi) ^2} { \begin{bmatrix} -1 + ( -1)^n \end{bmatrix}} cos { \large n \pi x \over 2} + { \large 1 \over n \pi} { \begin{bmatrix} -1 + (-1)^{n+1} \end{bmatrix}} sen { \large n \pi x \over 2} \end{Bmatrix}} !$

!$ 1 + \displaystyle \sum_{n=1}^\infty {\begin{Bmatrix} { \large 1 \over ( n \pi) ^2} { \begin{bmatrix} -1 + ( -1)^n \end{bmatrix}} cos { \large n \pi x \over 2} + { \large 1 \over n \pi} { \begin{bmatrix} -1 + (-1)^{n+1} \end{bmatrix}} sen { \large n \pi x \over 2} \end{Bmatrix}} !$

!$ 1 + \displaystyle \sum_{n=1}^\infty {\begin{Bmatrix} { \large 2 \over n \pi} { \begin{bmatrix} -1 + ( -1)^n \end{bmatrix}} cos { \large n \pi x \over 2} + { \large 1 \over (n \pi)^2} { \begin{bmatrix} -1 + (-1)^{n+1} \end{bmatrix}} sen { \large n \pi x \over 2} \end{Bmatrix}} !$

!$ 1 + \displaystyle \sum_{n=1}^\infty {\begin{Bmatrix} { \large 1 \over ( n \pi)} { \begin{bmatrix} -1 + ( -1)^n \end{bmatrix}} cos { \large n \pi x \over 2} + { \large 1 \over (n \pi)^2} { \begin{bmatrix} -1 + (-1)^{n+1} \end{bmatrix}} sen { \large n \pi x \over 2} \end{Bmatrix}} !$

!$ 1 + \displaystyle \sum_{n=1}^\infty {\begin{Bmatrix} { \large 2 \over ( n \pi) ^2} { \begin{bmatrix} -1 + ( -1)^n \end{bmatrix}} sen { \large n \pi x \over 2} + { \large 1 \over n \pi} { \begin{bmatrix} -1 + (-1)^{n+1} \end{bmatrix}} cos { \large n \pi x \over 2} \end{Bmatrix}} !$