Answer
$(-\infty, 4) \cup (4, +\infty)$
Work Step by Step
The denominator cannot be zero since division of zero is undefined.
The number 4 makes the denominator zero.
Thus, the domain of the given function is the set of all real numbers except $4$. In interval notation, the domain is:
$(-\infty, 4) \cup (4, +\infty)$
