buktikan gambar berikut

sinA-sinB=2 Cos(A+B)sin(A-B)
sinA+SinB=2 sin(A+B)cos(A-B)
Tan itu sama dengan cos per sin udah tolong hitung sendiri ya

(sin A - sin B)/(sin A + sin B)
= (2 cos 1/2 (A + B) sin 1/2 (A - B)) / (2 sin 1/2 (A + B) cos 1/2 (A - B))
= 2/2 . (cos 1/2 (A + B))/(sin 1/2 (A - B)) . (sin 1/2 (A + B))/(cos 1/2 (A - B))
= 1 . cot 1/2 (A + B) . tan 1/2 (A - B)
= 1/(tan 1/2 (A + B)) . tan 1/2 (A - B)
= (tan 1/2 (A - B)) / (tan 1/2 (A + B))