1. The problem statement, all variables and given/known data I have a question. I need to know the integral dxdydz/(y+z) where x>=0, y>=0, z>=0. 2. Relevant equations It is bounded by x + y + z = 1. The transformations I need to use are x=u(1-v), y=uv(1-w), z=uvw. 3. The attempt at a solution y+z = uv. J = uv(v-v^2+uv) So I get the integral (v-v^2+uv)dudvdw. But I don't know which bounds I need to use. Is this correct and how can I know the bounds?