The derivative of \(\tan ^{-1}\left(x^2\right)\) w.r.t. \(x\) is :

\(\frac{\mathrm{x}}{1+\mathrm{x}^4}\)

\(\frac{2 \mathrm{x}}{1+\mathrm{x}^4}\)

\(-\frac{2 x}{1+x^4}\)

\(\frac{1}{1+\mathrm{x}^4}\)