The solution of $\frac{1}{2} +cosx + cos2x + cos3x + cos4x = 0$ is
$x=\frac{2n\pi}{9},n\in I,n\neq 9m,m\in I$
$x=\frac{2n\pi}{9},n\in I,n= 9m,m\in I$
$x=\frac{n\pi}{9}+\frac{\pi}{2},n\in I$
$x=\frac{2n\pi}{3}+\frac{\pi}{6},n\in I$
The value of $\theta $ satisfying the given equation $\cos \theta + \sqrt 3 \sin \theta = 2,$ is
Minimum value of the function $f(x) = \left| {\sin \,x + \cos \,x + \tan \,x + \cot \,x + \sec \,x + \ cosec\ x} \right|$ is equal to
If $\cos 7\theta = \cos \theta - \sin 4\theta $, then the general value of $\theta $ is
If $\sin x=\frac{3}{5}, \cos y=-\frac{12}{13},$ where $x$ and $y$ both lie in second quadrant, find the value of $\sin (x+y)$.
The solution set of $(5 + 4\cos \theta )(2\cos \theta + 1) = 0$ in the interval $[0,\,\,2\pi ]$ is