\[
\boxed{
{\frac {\rm d}{{\rm d}x}}y \left( x \right) ={\frac {x \left( -{x}^{2}+2\,{x}^{2}y \left( x \right) -2\,{x}^{4}+1 \right) }{y \left( x \right) -{x}^{2}}}=0}
\]