sin(x+y)-sin(x-y)=2sinycosx

Question

I can't seem to figure out how to solve the right side of this to= sin(x+y)-sin(x-y)? Please help! Thx.

Answer 1

angle addition and subtraction

formula for sin:

sin x cos y + cos x sin y -

( sin x cos y - cos x sin y) =

sin x cos y + cos x sin y

- sinx cos y + cos x sin y

= 2 cos x sin y