Question

sin-1x +sin-1y -cos-1z = pi ,x+y+z =?

Answer 1

sin-1x +sin-1y=pi+cos-1z
sin(sin-1x+sin-1y)=sin(pi+cos-1z)=sin(-sin-1z)
(x+y)/(1-xy)=-z
-x-y=z-xyz
so...x+y+z=xyz