#### Answer

Not a polynomial

#### Work Step by Step

A polynomial function is in the form of $a_nx_n+a_{n-1}x_{n-1}+...+a_1x+a_0$ where $a_n\ne0$ and the coefficients are real. Then $a_n$ is the leading coefficient, $n$ is the degree and $a_n$ is the leading coefficient.
Hence, here the function is not polynomial because in polynomials, negative powers are not allowed.