The sum of all values of $\theta \, \in \,\left( {0,\frac{\pi }{2}} \right)$ satisfying ${\sin ^2}\,2\theta  + {\cos ^4}\,2\theta  = \frac{3}{4}$ is

  • [JEE MAIN 2019]
  • A

    $\pi $

  • B

    $\frac{{5\pi }}{4}$

  • C

    $\frac{{\pi }}{2}$

  • D

    $\frac{{3\pi }}{8}$

Similar Questions

Prove that $\cos ^{2} 2 x-\cos ^{2} 6 x=\sin 4 x \sin 8 x$

If $A + B + C = \pi ,$ then $\cos \,\,2A + \cos \,\,2B + \cos \,\,2C = $

Let $S=\left\{x \in(-\pi, \pi): x \neq 0, \pm \frac{\pi}{2}\right\}$. The sum of all distinct solutions of the equation $\sqrt{3} \sec x+\operatorname{cosec} x+2(\tan x-\cot x)=0$ in the set $S$ is equal to

  • [IIT 2016]

If $A + B + C = \pi \,(A,B,C > 0)$ and the angle $C$ is obtuse then

If $x + y + z = {180^o},$ then $\cos 2x + \cos 2y - \cos 2z$ is equal to