\[
\boxed{
{\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left( x \right) +a \left( {\frac {\rm d}{{\rm d}x}}y \left( x \right)  \right)  \left| {\frac {\rm d}{{\rm d}x}}y \left( x \right)  \right| +b{\frac {\rm d}{{\rm d}x}}y \left( x \right) +cy \left( x \right) =0}
\]