If ${\rm{cosec}}\theta = \frac{{p + q}}{{p - q}},$ then $\cot \,\left( {\frac{\pi }{4} + \frac{\theta }{2}} \right) = $
$\sqrt {\frac{p}{q}} $
$\sqrt {\frac{q}{p}} $
$\sqrt {pq} $
$pq$
$\frac{1}{{\sin 10^\circ }} - \frac{{\sqrt 3 }}{{\cos 10^\circ }} =$
$\cos 20^\circ \cos 40^\circ \cos 80^\circ = $
The exact value of $cos^273^o + cos^247^o + (cos73^o . cos47^o )$ is
If $\cos \,(\theta - \alpha ) = a,\,\,\sin \,(\theta - \beta ) = b,\,\,$then ${\cos ^2}(\alpha - \beta ) + 2ab\,\sin \,(\alpha - \beta )$ is equal to
Number of values of $ x \in \left[ {0,2\pi } \right]$ satisfying the equation $cotx - cosx = 1 - cotx. cosx$