\[ y'(x)=\frac {\csc (y(x)) \left (\frac {1}{2} x^3 \log (x) \cos (2 y(x))+\frac {1}{2} x^3 \log (x)-\cos (y(x))\right )}{x \log (x)} \] ✓ Mathematica : cpu = 0.677796 (sec), leaf count = 63
\[\left \{\left \{y(x)\to -\sec ^{-1}\left (\frac {-x^3+3 x^3 \log (x)-9 c_1}{9 \log (x)}\right )\right \},\left \{y(x)\to \sec ^{-1}\left (\frac {-x^3+3 x^3 \log (x)-9 c_1}{9 \log (x)}\right )\right \}\right \}\] ✓ Maple : cpu = 0.824 (sec), leaf count = 27
\[\left \{y \left (x \right ) = \arccos \left (\frac {9 \ln \left (x \right )}{3 x^{3} \ln \left (x \right )-x^{3}+9 c_{1}}\right )\right \}\]