1. The problem statement, all variables and given/known data Use implicit differentiation to find y' if (x-y)/(x+y)=(x/y)+1. Now show that there are, in fact, no points on that curve, so the derivative you calculated is meaningless. 2. Relevant equations 3. The attempt at a solution I managed to get it into the form: dy/dx = [(x+y)2-2y3]/[(x)(-2y2+(x+y)2] This doesn't seem like it proves anything though. Someone help please!