\[ y''(x)=-\csc (x) y'(x) \left (\sin ^2(x)-\cos (x)\right )-y(x) \sin ^2(x) \] ✓ Mathematica : cpu = 0.141609 (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 = 0.153 (sec), leaf count = 31
\[\left \{y \left (x \right ) = \left (c_{1} \sin \left (\frac {\sqrt {3}\, \cos \left (x \right )}{2}\right )+c_{2} \cos \left (\frac {\sqrt {3}\, \cos \left (x \right )}{2}\right )\right ) {\mathrm e}^{\frac {\cos \left (x \right )}{2}}\right \}\]