asked 127k views
3 votes
Prove 2SinAsinB =cos(A-B)-cos(A+B)

asked
User Mhesabi
by
7.6k points

1 Answer

3 votes
Right side of the equation:
cos ( A - B ) - cos ( A + B ) =
= cos A cos B + sin A sin B - ( cos A cos B - sin A sin B ) =
= cos A cos B + sin A sin B - cos A cos B + sin A sin B =
= 2 sin A sin B - left side of the equation ( correct )
answered
User NendoTaka
by
8.4k points
Welcome to Qamnty — a place to ask, share, and grow together. Join our community and get real answers from real people.