The roots of the equation $1 - \cos \theta = \sin \theta .\sin \frac{\theta }{2}$ is
$k\pi ,k \in I$
$2k\pi ,k \in I$
$k\frac{\pi }{2},k \in I$
None of these
The general solution of $a\cos x + b\sin x = c,$ where $a,\,\,b,\,\,c$ are constants
All possible values of $\theta \in[0,2 \pi]$ for which $\sin 2 \theta+\tan 2 \theta>0$ lie in
If $(1 + \tan \theta )(1 + \tan \phi ) = 2$, then $\theta + \phi =$ ....$^o$
$\alpha=\sin 36^{\circ}$ is a root of which of the following equation
The number of values of $\alpha $ in $[0, 2\pi]$ for which $2\,{\sin ^3}\,\alpha - 7\,{\sin ^2}\,\alpha + 7\,\sin \,\alpha = 2$ , is