I arrived at this sum or trigonometric functions that I need to turn into a product in order to continue the exercise. How do I do that?
$$\sin{x}\cos{(x+y)} -\cos{x}\sin{(x+y)}$$
I know of the identities of $\cos{(a \pm b)}$ and $\sin{(a \pm b)}$, but I can't figure the solution out.