Posted by Jane on Wednesday, January 7, 2009 at 12:33pm.
2y(dy/dx) - 2x = 0
dy/dx = 2x/(2y) = x/y
y'' = (y(1) - x(y'))/y^2
= (y - x(x/y))/y^2
= (y^2 - x^2)/y^3
you had y^2 at the bottom of your y''
did you notice that there was a y in the denominator of your top?