Answer
See below.
Work Step by Step
The domain of the function is all the real numbers except $0$ and $3$, which can be represented as $(-\infty,0)\cup(0,3)\cup(3,\infty)$.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.