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