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