Выражение: sin(x+y)+sin(x-y)/sin(x+y)-sin(x-y)

sin^2(x+y) + sin(x-y) - sin(x-y)(x+y) / sin(x-y)
(sin(x+y)(sin(x+y) + sin(x-y)-sin(x-y))) / sin(x+y);
sin^2(x+y) / sin(x + y) = sin(x+y)