Answer
Domain: All real numbers.
Vertical asymptotes: None.
Horizontal asymptotes: $y=3$
Work Step by Step
Domain:
$x^2 +1 \ne 0$
$x^2\ne-1$
$x\ne \pm i$
All real numbers.
Identify vertical asymptotes. These occur at the zeros of the denominator of the function:
No vertical asymptotes.
Identify any horizontal asymptotes by describing the behavior as x goes to infinity:
$f(x)\rightarrow 3$ as $ x \rightarrow \infty$
$y=3$
