\[
\boxed{
{\frac {\rm d}{{\rm d}x}}y \left( x \right) =2\,{\frac {a}{-{x}^{2}y \left( x \right) +2\,a \left( y \left( x \right)  \right) ^{4}{x}^{2}-16\,{a}^{2}x \left( y \left( x \right)  \right) ^{2}+32\,{a}^{3}}}=0}
\]