Mathematics - Inverse Trigonometric Functions Question with Solution | TestHub

If $\mathrm{S}={\sum }_{\mathrm{r}=1}^{50}{\tan }^{-1}\left(\frac{2\mathrm{r}}{2+{\mathrm{r}}^2+{\mathrm{r}}^4}\right)={\tan }^{-1}\left(\frac{\lambda }{\mu }\right)$, where $\left(\frac{\lambda }{\mu }\right)$ is in simplest form, then $\mu -\lambda =$