The number of integral values of $k$, for which the equation $7\cos x + 5\sin x = 2k + 1$ has a solution, is
$4$
$8$
$10$
$12$
If $\alpha,-\frac{\pi}{2}<\alpha<\frac{\pi}{2}$ is the solution of $4 \cos \theta+5 \sin \theta=1$, then the value of $\tan \alpha$ is
Number of solution $(s)$ of the equation ${\cos ^2}2x + {\cos ^2}\frac{{5x}}{4} = \cos 2x\,{\cos ^2}5x$ in $\left[ {0,\frac{\pi }{3}} \right]$ is
$sin^{2n}x + cos^{2n}x$ lies between
If $\sec 4\theta - \sec 2\theta = 2$, then the general value of $\theta $ is
The number of solutions of equation $3cos^2x - 8sinx = 0$ in $[0, 3\pi]$ is