Answer
Not a polynomial.
Work Step by Step
First, we simplify:
$$\frac{x^2 -5}{x^3} = x^{-1} -5x^{-3}$$
By definition, a polynomial is a function containing only terms where x is raised to a positive, integer power or constants. x is raised to the negative third power. Because this is not a positive power, it is not a polynomial.
