\[
\boxed{
 \left( y \left( x \right)  \right) ^{2} \left( {\frac {\rm d}{{\rm d}x}}y \left( x \right)  \right) ^{2}-4\,ay \left( x \right) {\frac {\rm d}{{\rm d}x}}y \left( x \right) + \left( y \left( x \right)  \right) ^{2}-4\,ax+4\,{a}^{2}=0}
\]