Is $\sqrt{x}+x^2$ a polynomial? Use exponent rules to justify your answer.

It is a polynomial because $x^2$ dominates, and the radical term can be ignored when considering the degree

It is not a polynomial only when $x$ is negative; otherwise, it behaves like a polynomial for positive values of $x$

It is a polynomial because squaring the expression gives integer exponents

It is not a polynomial because $\sqrt{x}=x^{\frac{1}{2}}$ has a fractional exponent