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