\[
\boxed{
{\frac {\rm d}{{\rm d}x}}y \left( x \right) =-{\frac {y \left( x \right) }{\ln  \left( y \left( x \right)  \right) } \left( -1/2\,{\frac { \left( \ln  \left( y \left( x \right)  \right)  \right) ^{2}}{x}}-{\it \_F1} \left( x \right)  \right) }=0}
\]