1. The problem statement, all variables and given/known data (dy/dx)^2 = (1-y^2) / (1-x^2) 2. Relevant equations Separating the variables I arrive with: dy/sqrt(1-y^2) = dx/sqrt(1-x^2) By integration on both sides by trigonometric substitution and putting it in a general solution: Arcsin y - Arcsin x = C 3. The attempt at a solution If I want to simplify more. Would it be right if I write: Arcsin (y-x) = C Multiply sin on both sides: y-x = C would be my final answer.