The value of ,$\sqrt 3 \, cosec\, 20^o - sec\, 20^o $ is :
$2$
$\frac{{2\,\sin \,20^\circ }}{{\sin \,40^\circ }}$
$4$
$\frac{{4\,\sin \,20^\circ }}{{\sin \,40^\circ }}$
The value of $\tan 7\frac{1}{2}^\circ $ is equal to
$2\sin A{\cos ^3}A - 2{\sin ^3}A\cos A = $
If $3\cos \theta + 4\sin \theta = 5$ then $3\sin \theta - 4\cos \theta $ is
If ${\cos ^6}\alpha + {\sin ^6}\alpha + K\,{\sin ^2}2\alpha = 1,$ then $K =$
If $\alpha$, $\beta$,$\gamma$ are positive number such that $\alpha + \beta = \pi$ and $\beta + \gamma = \alpha$, then $tan\ \alpha$ is equal to - (where $\gamma \ne n\pi ,n \in I$ )