If $\sin 6\theta = 32{\cos ^5}\theta \sin \theta - 32{\cos ^3}\theta \sin \theta + 3x,$ then $x = $
$\cos \theta $
$\cos 2\theta $
$\sin \theta $
$\sin 2\theta $
$\frac{{\cos A}}{{1 - \sin A}} = $
$\sqrt {\frac{{1 - \sin A}}{{1 + \sin A}}} = $
If $A + B + C = \pi ,$ then ${\tan ^2}\frac{A}{2} + {\tan ^2}\frac{B}{2} + $${\tan ^2}\frac{C}{2}$ is always
The exact value of $cos^273^o + cos^247^o + (cos73^o . cos47^o )$ is
${\rm{cosec }}A - 2\cot 2A\cos A = $