Answer
$\sqrt{3}$
Work Step by Step
We use the subtraction formula for tangent, $\tan(s-t)=\frac{\tan s-\tan t}{1+\tan s \tan t}$, with $s=73^\circ$ and $t=13^\circ$.
$\frac{\tan 73^\circ-\tan 13^\circ}{1+\tan 73^\circ \tan 13^\circ}$
$=\tan(73^\circ-13^\circ)$
$=\tan(60^\circ)$
$=\sqrt{3}$
