Prove that:
R.H.S. = = = 2 sinA cosB = L.H.S.Hence, 2 sinA cosB = sin (A+B) + sin (A - B)
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: