Answer
$$y' = \tanh^{-1} \left(x\right)+\frac{x}{1-x^2}$$
Work Step by Step
Given $$y=x\tanh^{-1}x$$
Then
\begin{align*}
y'&=\frac{d}{dx}\left(x\right)\tanh^{-1} \left(x\right)+\frac{d}{dx}\left(\tanh^{-1} \left(x\right)\right)x\\
&= \tanh^{-1} \left(x\right)+\frac{x}{1-x^2}
\end{align*}