Solve for θ $\csc 3θ = 5 \sin 3\theta$ Solve for $θ$, find all solutions.
$\csc 3θ = 5 \sin 3θ$
I get stuck when I do this:
$$\frac{1}{\sin 3θ} = 5\sin3θ$$
$$\frac{1}{5} = (\sin 3θ)^2$$
How do I simplify the right side? 

You'd get $\frac{1}{5} = \sin^2{(3\theta)}$, solving for $\theta$ you can obtain $\sin{(3\theta)} = \pm \frac{\sqrt{5}}{5} \implies \theta = \frac{\pi n}{3} \pm \frac{\arcsin{(\frac{\sqrt{5}}{5}})}{3}$.
You can then use the above to find all our solutions in what I'd assume is the interval $[0,2\pi)$.
