Given function is:
[tex]f(x)=-\frac{x^3}{6}-\frac{6}{x^2}\ldots(1)[/tex]A polynomial is an algebraic expression that involves only positive integer exponents for the variables.
A polynomial function is of the form:
[tex]p(x)=a_nx^n_{}+a_{n-1}x^{n-1}+a_{n-2}x^{n-2}+\cdots+a_0[/tex]Solving equation (1)
[tex]\begin{gathered} f(x)=-\frac{x^3}{6}-\frac{6}{x^2} \\ =-\frac{x^5+36}{6x^2} \\ =-\frac{x^{-2}(x^5+36)}{6} \end{gathered}[/tex]We can see that the function has a negative exponent.
The given function is not a polynomial function.