## Precalculus (6th Edition) Blitzer

$(-\infty,-4)\cup(-4,4)\cup(4,\infty)$
Step 1. The domain requirement is that the denominator can not be zero, which gives $x\ne\pm4$. Thus the domain can be written as $(-\infty,-4)\cup(-4,4)\cup(4,\infty)$ Step 2. See graph.