\[ y''(x)=\left (3 \sin ^2(x)+1\right ) \csc (x) \sec (x) y'(x)+y(x) \tan ^2(x) \] ✓ Mathematica : cpu = 0.239783 (sec), leaf count = 42
\[\left \{\left \{y(x)\to c_2 \cos ^{\frac {1}{2} \left (\sqrt {13}-3\right )}(x)+c_1 \cos ^{\frac {1}{2} \left (-3-\sqrt {13}\right )}(x)\right \}\right \}\] ✓ Maple : cpu = 0.433 (sec), leaf count = 29
\[ \left \{ y \left ( x \right ) ={\it \_C1}\, \left ( \cos \left ( x \right ) \right ) ^{-{\frac {3}{2}}+{\frac {\sqrt {13}}{2}}}+{\it \_C2}\, \left ( \cos \left ( x \right ) \right ) ^{-{\frac {3}{2}}-{\frac {\sqrt {13}}{2}}} \right \} \]