If $\tan 3 \theta=\cot \theta$, then $\theta=$

The general solution of the equation $\sqrt{3} \cos \theta+\sin \theta=\sqrt{2}$ is

Let $P=\{\theta / \sin \theta-\cos \theta=\sqrt{2} \cos \theta\}$ and $Q=\{\theta / \sin \theta+\cos \theta=\sqrt{2} \sin \theta\}$ be two sets, then

The number of values of $x$ in the interval $(0,5 \pi)$ satisfying the equation $3 \sin ^2 x-7 \sin x+2=0$