\[
\boxed{
{\frac {\rm d}{{\rm d}x}}y \left( x \right) ={\frac {y \left( x \right)  \left( -\cosh \left(  \left( 1+x \right) ^{-1} \right) x+\cosh \left(  \left( 1+x \right) ^{-1} \right) -x+{x}^{2}y \left( x \right) -{x}^{2}+{x}^{3}y \left( x \right)  \right) }{ \left( x-1 \right) x\cosh \left(  \left( 1+x \right) ^{-1} \right) }}=0}
\]