\[
\boxed{
{\frac {\rm d}{{\rm d}x}}y \left( x \right) ={\frac { \left( x \left( y \left( x \right)  \right) ^{2}+1 \right) ^{3}}{{x}^{4} \left( x \left( y \left( x \right)  \right) ^{2}+1+x \right) y \left( x \right) }}=0}
\]