Answer
$y'= \dfrac{2x}{x^2-1}$
Work Step by Step
In order to derivate this function you have to apply the chain rule
Let's make a «u» substitution to make it easier
$f(u) = \ln(u)$
$u = x^2-1$
Derivate the function:
$f'(u) = \dfrac{1}{u} \times u'$
Now let's find u'
$u' =2x$
Then undo the substitution, simplify and get the answer::
$f'(x)= \dfrac{2x}{x^2-1}$