જો $\left| {\,\begin{array}{*{20}{c}}{\cos (A + B)}&{ - \sin (A + B)}&{\cos 2B}\\{\sin A}&{\cos A}&{\sin B}\\{ - \cos A}&{\sin A}&{\cos B}\end{array}\,} \right| = 0$ તો $B =$

જો $(2\cos x - 1)(3 + 2\cos x) = 0,\,0 \le x \le 2\pi $, તો $x = $

જો $\tan (\cot x) = \cot (\tan x),$ તો $\sin 2x =$

સમીકરણ $\sin x + \sin y + \sin z = - 3\, , \,$$ 0 \le x \le 2\pi ,$ $0 \le y \le 2\pi ,$ $0 \le z \le 2\pi $ માટેના બીજની સંખ્યા . . . . છે.

$\tan 2 x=-\cot \left(x+\frac{\pi}{3}\right)$ ઉકેલો.

ધારોકે $S=\left\{x \in\left(-\frac{\pi}{2}, \frac{\pi}{2}\right): 9^{1-\tan ^2 x}+9^{\tan ^2 x}=10\right\}$, અને $\beta=\sum_{x \in S} \tan ^2\left(\frac{x}{3}\right)$,તો $\frac{1}{6}(\beta-14)^2=.........$