Question

PLEASE HELP Trig Idenities

Answer 1

`(\sin(A+B))/(\sin(A-B))=(\sin A\cos B+\cos A\sin B)/(\sin A\cos B-\cos A\sin B)`

Divide through all terms by
`\cos A\cos B`. Then, for instance, the first term in the numerator becomes


`(\sin A\cos B)/(\cos A\cos B)=(\sin A)/(\cos A)=\tan A`

All other terms reduce similarly, giving the final product


`(\tan A+\tan B)/(\tan A-\tan B)`