1. The problem statement, all variables and given/known data I have this question given: 2. Relevant equations 3. The attempt at a solution So I used change of variables, fairly straightforward, I set a = x+y+z b = x+2y c = y - 3z computed the jacobian, and got the new ranges. Anyway, so the solution has the order of integration as int int int (sqrt a dc db da) why is it from dc db da? I was wrong at that part because i used da db dc, how do you find out what the order of integration should be?