Question

Prove that sina+ sinB/sin A-sin B = tan (A + B)/2.Cos[A-B/2)​

Answer 1

Answer:

See the answer below... Explanation: sinA+sinB=x ⇒2⋅sin(A+B2)⋅cos(A −B2)=x ...(1). cosA+cosB=y ⇒2⋅cos(A+B2)⋅cos( A−B2)=y .