\[
\boxed{
4\, \left( {\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left( x \right)  \right) y \left( x \right) -3\, \left( {\frac {\rm d}{{\rm d}x}}y \left( x \right)  \right) ^{2}+4\,y \left( x \right) =0}
\]