1 Answers
62if n is an integer...
then you have to break this integral in n parts...
\int_{0}^{\pi}{\sin 0}+\int_{\pi}^{2\pi}{\sin 1}+\int_{2\pi}^{3\pi}{\sin 2}...+\int_{(n-1)\pi}^{n\pi}{\sin (n-1)} \\ = \pi\left\{\sin 1+ \sin 2+\sin 3.... +\sin n \right\}