y (t) = \frac{1}{2} + \frac{1}{π} \sum_{n = 1}^{\infty} \frac{{(- 1)}^{n + 1}}{n} s i n (n t)

${y(t) = \frac {1} {2} + \frac {1} {\pi} \sum\limits_{ n = 1}^\infty \frac {{(-1)}^{n + 1}} {n} sin(nt)}$

Error