$$\displaystyle\frac{d}{d x } \left(2 \ln ( x \sqrt{ { x }^{ 2 } -1 } ) \right)$$
$\frac{2\left(2x^{2}-1\right)}{x\left(x^{2}-1\right)}$
$\frac{2\left(-2x^{4}+x^{2}-1\right)}{\left(x\left(x^{2}-1\right)\right)^{2}}$
