The maximum value of the function $f(x) = 3\sin x + 4\cos x$ is

The value of the following is $\cos 24^{\circ} + \cos 55^{\circ} + \cos 125^{\circ} + \cos 204^{\circ} + \cos 300^{\circ}$

If $\theta$ lies in the second quadrant,then the value of $\sqrt{\frac{1 - \sin \theta}{1 + \sin \theta}} + \sqrt{\frac{1 + \sin \theta}{1 - \sin \theta}}$ is:

The equation $\sec^2 \theta = \frac{4xy}{(x + y)^2}$ is only possible when

$(m + 2)\sin \theta + (2m - 1)\cos \theta = 2m + 1$,then $\tan \theta$ is equal to:

$\sin^4 \frac{\pi}{8} + \sin^4 \frac{3\pi}{8} + \sin^4 \frac{5\pi}{8} + \sin^4 \frac{7\pi}{8} = $