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