\[
\boxed{
 \left( {\frac {\rm d}{{\rm d}x}}y \left( x \right)  \right) ^{2}-xy \left( x \right) {\frac {\rm d}{{\rm d}x}}y \left( x \right) + \left( y \left( x \right)  \right) ^{2}\ln  \left( ay \left( x \right)  \right) =0}
\]