The solution of $\frac{1}{2} +cosx + cos2x + cos3x + cos4x = 0$ is
$x=\frac{2n\pi}{9},n\in I,n\neq 9m,m\in I$
$x=\frac{2n\pi}{9},n\in I,n= 9m,m\in I$
$x=\frac{n\pi}{9}+\frac{\pi}{2},n\in I$
$x=\frac{2n\pi}{3}+\frac{\pi}{6},n\in I$
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
If ${\tan ^2}\theta - (1 + \sqrt 3 )\tan \theta + \sqrt 3 = 0$, then the general value of $\theta $ is
General solution of $\tan 5\theta = \cot 2\theta $ is $($ where $n \in Z )$
If $tan(\pi sin \theta)$ $= cot(\pi cos \theta)$, then $\left| {\cot \left( {\theta - \frac{\pi }{4}} \right)} \right|$ is -
Number of solution$(s)$ of the equation $ln(1 + sin^2x) = 1 -ln(5 + x^2)$ is -