\[ y''(x)=-\csc (x) y'(x) \left (\sin ^2(x)-\cos (x)\right )-y(x) \sin ^2(x) \] ✓ Mathematica : cpu = 0.15895 (sec), leaf count = 45
\[\left \{\left \{y(x)\to e^{\frac {\cos (x)}{2}} \left (c_1 \cos \left (\frac {1}{2} \sqrt {3} \cos (x)\right )+c_2 \sin \left (\frac {1}{2} \sqrt {3} \cos (x)\right )\right )\right \}\right \}\]
✓ Maple : cpu = 0.218 (sec), leaf count = 31
\[ \left \{ y \left ( x \right ) ={{\rm e}^{{\frac {\cos \left ( x \right ) }{2}}}} \left ( \cos \left ( {\frac {\sqrt {3}\cos \left ( x \right ) }{2}} \right ) {\it \_C2}+\sin \left ( {\frac {\sqrt {3}\cos \left ( x \right ) }{2}} \right ) {\it \_C1} \right ) \right \} \]