Prove that: (sin²A-sin²B)/((sin A cos A)-(sin B cos B))=tan(A+B)?

1 Answer
Jun 7, 2018

LHS=(sin²A-sin²B)/((sin A cos A)-(sin B cos B))

=(2sin(A+B)sin(A-B))/((2sin A cos A)-(2sin B cos B))

=(2sin(A+B)sin(A-B))/(sin 2A -sin2 B)

=(2sin(A+B)sin(A-B))/(2cos(A+B) sin(A- B))

=tan(A+B)=RHS