$$\frac { e ^ { \tan ^ { - 1 } x } } { 1 + x ^ { 2 } } d x$$
$\frac{dxe^{\arctan(x)}}{x^{2}+1}$
$\frac{d\left(1+x-x^{2}\right)e^{\arctan(x)}}{\left(x^{2}+1\right)^{2}}$
