The solution set of the system of equation
$x\,\, + \,\,y\,\, = \,\,\frac{{2\pi }}{3},\,{\rm{cos}}\,{\rm{x + }}\,{\rm{ cos}}\,{\rm{y}}\,{\rm{ = }}\,\frac{3}{2},$ where $x$ and $y$ are real in
a finite non-empty set
null set
$\infty $
none of these
Let $f(x) = \cos \sqrt {x,} $ then which of the following is true
The sum of all $x \in[0, \pi]$ which satisfy the equation $\sin x+\frac{1}{2} \cos x=\sin ^2\left(x+\frac{\pi}{4}\right)$ is
Find the general solution of the equation $\cos 4 x=\cos 2 x$
If $|k|\, = 5$ and ${0^o} \le \theta \le {360^o}$, then the number of different solutions of $3\cos \theta + 4\sin \theta = k$ is
If $\sec 4\theta - \sec 2\theta = 2$, then the general value of $\theta $ is