Prove that:
Prove that:2 cosA sinB = sin (A + B) - sin (A - B)
Prove that:2 cosA cosB = cos (A + B) + cos (A - B)
Prove that:-2 sinA sinB = cos (A + B) - cos (A - B)
Prove the following:
Let R.H.S. = = sin (x + y) - sin (x - y) = = sin C - sin D = L.H.S.Hence,