\[
\boxed{
{\frac {\rm d}{{\rm d}x}}y \left( x \right) =1/2\,{\frac {-2\,\cos \left( x \right) x+2\,{x}^{2}\sin \left( x \right) +2\,x+2\, \left( y \left( x \right)  \right) ^{2}+4\,y \left( x \right) \cos \left( x \right) x-4\,xy \left( x \right) +{x}^{2}\cos \left( 2\,x \right) +3\,{x}^{2}-4\,{x}^{2}\cos \left( x \right) }{x}}=0}
\]