## Precalculus (6th Edition) Blitzer

Domain: $(-\infty,-3)\cup(-3,1)\cup(1,\infty)$ See graph.
Step 1. Factor the function as $f(x)=\frac{(x+1)}{(x+3)(x-1)}$; there are no common factors. Step 2. The domain requirement is that the denominator can not be zero, which gives $x\ne-3,1$. Thus the domain can be written as: $(-\infty,-3)\cup(-3,1)\cup(1,\infty)$ Step 3. We can identify vertical asymptotes as $x=-3$ and $x=1$ Step 4. See graph.