The solution of equation ${\cos ^2}\theta + \sin \theta + 1 = 0$ lies in the interval
$\left( { - \frac{\pi }{4},\frac{\pi }{4}} \right)$
$\left( {\frac{\pi }{4},\frac{{3\pi }}{4}} \right)$
$\left( {\frac{{3\pi }}{4},\frac{{5\pi }}{4}} \right)$
$\left( {\frac{{5\pi }}{4},\frac{{7\pi }}{4}} \right)$
If $sin\, \theta = sin\, \alpha$ then $sin\, \frac{\theta }{3}$ =
The smallest positive angle which satisfies the equation $2{\sin ^2}\theta + \sqrt 3 \cos \theta + 1 = 0$, is
Let $S=\{x \in R: \cos (x)+\cos (\sqrt{2} x)<2\}$, then
Number of principal solution of the equation $tan \,3x - tan \,2x - tan\, x = 0$, is
The number of solutions of the equation $\sin x=$ $\cos ^{2} x$ in the interval $(0,10)$ is