#### Answer

$9^{\frac{1}{2}}=\sqrt 9=3$

#### Work Step by Step

For all positive numbers $a$, where $a\ne1$, and all positive numbers $x$, we know that $y=log_{a}x$ means the same as $x=a^{y}$.
Therefore, $log_{9}3=\frac{1}{2}$ means the same as $9^{\frac{1}{2}}=\sqrt 9=3$.