\[ y''(x)=-\csc (x) y'(x) \left (\sin ^2(x)-\cos (x)\right )-y(x) \sin ^2(x) \] ✓ Mathematica : cpu = 0.128542 (sec), leaf count = 52
\[\left \{\left \{y(x)\to c_1 e^{\frac {\cos (x)}{2}} \cos \left (\frac {1}{2} \sqrt {3} \cos (x)\right )+c_2 e^{\frac {\cos (x)}{2}} \sin \left (\frac {1}{2} \sqrt {3} \cos (x)\right )\right \}\right \}\] ✓ Maple : cpu = 0.133 (sec), leaf count = 31
\[y \relax (x ) = {\mathrm e}^{\frac {\cos \relax (x )}{2}} \left (\sin \left (\frac {\sqrt {3}\, \cos \relax (x )}{2}\right ) c_{1}+\cos \left (\frac {\sqrt {3}\, \cos \relax (x )}{2}\right ) c_{2}\right )\]