Fill in the blanks with the appropriate word, phrase, or symbol(s) from the following list.
$\text { multiply }\quad \text { divide } \quad \text { add } \quad \text { function } \quad \text { domain }\quad \text { rational } \quad \text { range } \quad \text { simplify}$
A rational ___________ is of the form $y=f(x)=\frac{p}{q}$, where $p$ and $q$ are polynomials and $q \neq 0$.