The general solution of $\sin x - 3\sin 2x + \sin 3x = $ $\cos x - 3\cos 2x + \cos 3x$ is
$n\pi + \frac{\pi }{8}$
$\frac{{n\pi }}{2} + \frac{\pi }{8}$
${( - 1)^n}\frac{{n\pi }}{2} + \frac{\pi }{8}$
$2n\pi + {\cos ^{ - 1}}\frac{3}{2}$
If $\cos 3x + \sin \left( {2x - \frac{{7\pi }}{6}} \right) = - 2$, then $x = $ (where $k \in Z$)
The number of solutions of the equation $2 \theta-\cos ^{2} \theta+\sqrt{2}=0$ is $R$ is equal to
For $n \in Z$ , the general solution of the equation
$(\sqrt 3 - 1)\,\sin \,\theta \, + \,(\sqrt 3 + 1)\,\cos \theta \, = \,2$ is
The only value of $x$ for which ${2^{\sin x}} + {2^{\cos x}} > {2^{1 - (1/\sqrt 2 )}}$ holds, is
The number of real solutions of the equation $2 \sin 3 x+\sin 7 x-3=0$, which lie in the interval $[-2 \pi, 2 \pi]$ is