Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

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.

share|improve this question

1 Answer 1

up vote 3 down vote accepted

Letting $a=x$ and $b=x+y$, you have $$\sin a\cos b-\cos a\sin b=\sin(a-b).$$

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.