y'(x)=\frac{-\exp \left(\frac{2 (x-y(x))^3 (y(x)+x)^3}{x^2-y(x)^2-1}\right)-x^2-2 x y(x)-y(x)^2}{\exp \left(\frac{2 (x-y(x))^3 (y(x)+x)^3}{x^2-y(x)^2-1}\right)-x^2-2 x y(x)-y(x)^2}