Indefinite Integration

$2 x \tan ^{-1} x-\log \left(1+x^2\right)+\mathrm{c}$, where c is a constant of integration.

$2\left(x \tan ^{-1} x-\log \left(1+x^2\right)\right)+\mathrm{c}$, where c is a constant of integration.

$x \tan ^{-1} x+\log \left(1+x^2\right)+\mathrm{c}$, where c is a constant of integration.

$2\left(x \tan ^{-1} x+\log \left(1+x^2\right)\right)+\mathrm{c}$, where c is a constant of integration.