\[
\boxed{
{\frac {\rm d}{{\rm d}x}}y \left( x \right) - \left( {\frac {{\it a3}\,{x}^{3}+{\it a2}\,{x}^{2}+{\it a1}\,x+{\it a0}}{{\it a3}\, \left( y \left( x \right)  \right) ^{3}+{\it a2}\, \left( y \left( x \right)  \right) ^{2}+{\it a1}\,y \left( x \right) +{\it a0}}} \right) ^{2/3}=0}
\]