If ${\sin ^2}\theta = \frac{{{x^2} + {y^2} + 1}}{{2x}}$, then $x$ must be
$-3$
$-2$
$1$
None of these
If $\tan \theta = \frac{{ - 4}}{3},$ then $\sin \theta = $
$\frac{{\sin \theta }}{{1 - \cot \theta }} + \frac{{\cos \theta }}{{1 - \tan \theta }} = $
If $\frac{{3\pi }}{4} < \alpha < \pi ,$ then $\sqrt {{\rm{cose}}{{\rm{c}}^2}\alpha + 2\cot \alpha } $ is equal to
If $A + C = B,$ then $\tan A\,\tan B\,\tan C = $
Find the radian measures corresponding to the following degree measures:
$-47^{\circ} 30^{\prime}$