\[
\boxed{
y \left( x \right) \ln  \left( {\frac {\rm d}{{\rm d}x}}y \left( x \right)  \right) +{\frac {\rm d}{{\rm d}x}}y \left( x \right) -y \left( x \right) \ln  \left( y \left( x \right)  \right) -xy \left( x \right) =0}
\]