1. The problem statement, all variables and given/known data What is the derivative of x^2 + y^2 = 2y, and find the tangent line to this equation at (1,1) 2. Relevant equations 3. The attempt at a solution I get y' = x / (1-y). However, how do I find the tangent line to this? When I plug in the values it divides by zero! (1 / (1-1)) Is this a trick question?