If $\frac{\sec \theta+\tan \theta}{\sec \theta-\tan \theta}=2 \frac{51}{79}$,then the value of $\sin \theta$ is

The minimum value of $(8 \sec^2 \theta + 2 \cos^2 \theta)$ is equal to :-

$\frac{\cos 17^\circ + \sin 17^\circ}{\cos 17^\circ - \sin 17^\circ} = $

$\tan 20^\circ \tan 40^\circ \tan 60^\circ \tan 80^\circ = $

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

From an aeroplane flying vertically over a straight horizontal road,the angles of depression of two consecutive milestones on opposite sides of the aeroplane are observed to be $30^{\circ}$ and $60^{\circ}$. Find the height of the aeroplane above the road in miles.