Answer
$ \frac{\sqrt (1-\cos^{2}\theta)}{\cos\theta}$
Work Step by Step
From ratio identity-
$\tan\theta$ = $ \frac{\sin\theta}{\cos\theta}$
$\tan\theta$ = $ \frac{\sqrt (1-\cos^{2}\theta)}{\cos\theta}$
[From Pythagorean identity, $\sin\theta$ can be written as $\sqrt (1-\cos^{2}\theta)$]
