Answer
$3xy^{2}$
Work Step by Step
Raising each term in the expression to the power of $1/2$, we obtain:
$(9x^{2}y^{4})^{\frac{1}{2}}$
=$(9)^{\frac{1}{2}}(x^{2})^{\frac{1}{2}}(y^{4})^{\frac{1}{2}}$
=$3(x^{2\times\frac{1}{2}})y^{4\times\frac{1}{2}}$
=$3(x^{1})(y)^{2}$
=$3xy^{2}$
