# Math Help - Need help with yet another trigo identity

1. ## Need help with yet another trigo identity

Hi Guys !

Here is yet another trigo identity which i simply can't figure it out

2. 1. Rewrite $\sin\alpha+\sin\beta$ using the sum-to-product rule.
2. Rewrite $\sin(\alpha+\beta)$ as $\sin(2(\alpha+\beta)/2)$ and further using the formula for double angle.
3. Factor out $2\sin((\alpha+\beta)/2)$ in the left-hand side.