# Solve $2\cos (2\theta) = 4\sin\theta$ for all values of $\theta$ between $0^{\circ}$ and $360^{\circ}$ [closed]

Solve $2\cos (2\theta) = 4\sin\theta$ for all values of $\theta$ between $0^{\circ}$ and $360^{\circ}$.

I have already tried to solve this but I am unsure as to finding out this particular one.

## closed as off-topic by Did, Dominik, Henrik, Vladhagen, LeucippusJan 13 '17 at 0:23

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$$4\sin\theta=2\cos2\theta=2(1-2\sin^2\theta)$$
$$\iff2\sin^2\theta+2\sin\theta-1=0$$ which is a Quadratic Equation in $\sin\theta$
Remember for real $\theta,-1\le\sin\theta\le1$