\[
\boxed{
{\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left( x \right) =-{\frac { \left(  \left( \sin \left( x \right)  \right) ^{2}-\cos \left( x \right)  \right) {\frac {\rm d}{{\rm d}x}}y \left( x \right) }{\sin \left( x \right) }}-y \left( x \right)  \left( \sin \left( x \right)  \right) ^{2}=0}
\]