I'm trying to prove this trigonometry identity, and I can solve it to the up until the last step, where I can't figure out which identity is being used to solve it.
This is the identity.
$$\tan\theta \cdot \cos^2\theta = \frac 12 \sin2\theta $$
Now I've solved the equation up to getting $$\sin\theta \cdot \cos\theta$$
Can someone help me out with how to get from that to
$$\frac 12 \sin2\theta $$