If $x = \sec \,\phi - \tan \phi ,y = {\rm{cosec}}\phi + \cot \phi ,$ then
$x = \frac{{y + 1}}{{y - 1}}$
$x = \frac{{y - 1}}{{y + 1}}$
$y = \frac{{1 - x}}{{1 + x}}$
None of these
If $\theta $ lies in the second quadrant, then the value of $\sqrt {\left( {\frac{{1 - \sin \theta }}{{1 + \sin \theta }}} \right)} + \sqrt {\left( {\frac{{1 + \sin \theta }}{{1 - \sin \theta }}} \right)} $
If $\cos A = \frac{{\sqrt 3 }}{2},$ then $\tan 3A = $
If $\tan \,(A - B) = 1,\,\,\,\sec \,(A + B) = \frac{2}{{\sqrt 3 }},$ then the smallest positive value of $B$ is
Prove that:
$\sin ^{2} \frac{\pi}{6}+\cos ^{2} \frac{\pi}{3}-\tan ^{2} \frac{\pi}{4}=-\frac{1}{2}$
Find the value of $\tan \frac{13 \pi}{12}$