\[ y''(x)=\frac {y(x) \sin (x)}{x \cos (x)-\sin (x)}-\frac {x \sin (x) y'(x)}{x \cos (x)-\sin (x)} \] ✓ Mathematica : cpu = 0.120646 (sec), leaf count = 15
\[\{\{y(x)\to c_1 x+c_2 \sin (x)\}\}\] ✓ Maple : cpu = 2.694 (sec), leaf count = 59
\[ \left \{ y \left ( x \right ) =\sin \left ( x \right ) \left ( \int \!{{\rm e}^{\int \!{\frac {-2\, \left ( \cos \left ( x \right ) \right ) ^{3}x+3\, \left ( \cos \left ( x \right ) \right ) ^{2}\sin \left ( x \right ) -\sin \left ( x \right ) }{\cos \left ( x \right ) \left ( \cos \left ( x \right ) x-\sin \left ( x \right ) \right ) \sin \left ( x \right ) }}\,{\rm d}x}}\cos \left ( x \right ) \,{\rm d}x{\it \_C2}+{\it \_C1} \right ) \right \} \]