Answer
The domain is {$x\in \mathbb{R}|x\ne\pm2$}.
Work Step by Step
The domain determined by first looking for the values of $x$ for which the function is not defined.
For a fraction to be defined the denominator can not equal to $0$:
$x^2-4\ne0$
$x^2\ne4$
$x=\pm\sqrt4$
$x\ne\pm2$
This requirement can be applied to define the domain:
Therefore the domain is {$x\in \mathbb{R}|x\ne\pm2$}.
