If $\alpha ,\,\beta ,\,\gamma ,\,\delta $ are the smallest positive angles in ascending order of magnitude which have their sines equal to the positive quantity $k$ , then the value of $4\sin \frac{\alpha }{2} + 3\sin \frac{\beta }{2} + 2\sin \frac{\gamma }{2} + \sin \frac{\delta }{2}$ is equal to
$2\sqrt {\left( {1 - k} \right)} $
$\frac{1}{2}\sqrt {\left( {1 + k} \right)} $
$2\sqrt {\left( {1 + k} \right)} $
None of these
One root of the equation $\cos x - x + \frac{1}{2} = 0$ lies in the interval
The general value of $\theta $ satisfying ${\sin ^2}\theta + \sin \theta = 2$ is
Common roots of the equations $2{\sin ^2}x + {\sin ^2}2x = 2$ and $\sin 2x + \cos 2x = \tan x,$ are
Let $S=\left\{x \in\left(-\frac{\pi}{2}, \frac{\pi}{2}\right): 9^{1-\tan ^2 x}+9^{\tan ^2 x}=10\right\}$ and $\beta=\sum_{x \in S} \tan ^2\left(\frac{x}{3}\right)$, then $\frac{1}{6}(\beta-14)^2$ is equal to