\[
\boxed{
{\frac {\rm d}{{\rm d}x}}y \left( x \right) =1/2\,{\frac {1+2\,\sqrt {4\,{x}^{2}y \left( x \right) +1}{x}^{3}+2\,{x}^{5}\sqrt {4\,{x}^{2}y \left( x \right) +1}+2\,{x}^{6}\sqrt {4\,{x}^{2}y \left( x \right) +1}}{{x}^{3}}}=0}
\]