Answer
It is a polynomial.
Degree: 3
Leading term: $x^3$
Constant term: 0
Work Step by Step
By definition, a polynomial is a function containing only terms where x is raised to a power or constants. x is raised to the third power, and x is raised to the first power in the term $4x$, so we see that it is a polynomial. The degree is equal to the exponent of the term with the highest exponent, so the degree is 3. The term that has the highest degree, $x^3$, is always the leading term. Finally, there are no constants listed, so the constant is 0.