# Solving $\cos(x/2) = \sin x$

Can anyone give me just a hint as to how to go about solving this? Yes it is for homework, but I don't want an answer, just a bit of guidance. I'm thinking the half angle formula for the first bit, but it doesn't seem to look right.

$$\cos(x/2)-\sin(x) = 0$$

Thanks!

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Let $y=\frac{x}{2}$, so that your equation is $$\cos(y)=\sin(2y).$$ Do you know any formulas that you can use here?
You could also try rewriting $\sin x$ as $$\sin x =2\sin \frac{x}{2}\cos\frac{x}{2}.$$