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