Answer
It is a polynomial function with a degree of $5$
Work Step by Step
A function $f(x)$ is a polynomial function when it has the form of
$$f(x)=a_nx^n+a_{n−1}x^{n−1}++a_1x+a_0$$
where $a_n\ne0$ and $n$ is an integer.
The given function has the correct form and $n=5$. Thus, it is a polynomial function with a degree of $5$.