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
$32$
$8$
$64$
$16$
If $\sqrt 2 \sec \theta + \tan \theta = 1,$ then the general value $\theta $ is
The equation $\sqrt 3 \sin x + \cos x = 4$ has
One root of the equation $\cos x - x + \frac{1}{2} = 0$ lies in the interval
$sin^{2n}x + cos^{2n}x$ lies between
The number of solutions of the equation $|\cot x|=\cot x+\frac{1}{\sin x}$ in the interval $[0,2 \pi]$ is