\[ y'(x)=\frac {\csc \left (\frac {y(x)}{2 x}\right ) \sec \left (\frac {y(x)}{2 x}\right ) \sec \left (\frac {y(x)}{x}\right ) \left (x^3 \sin \left (\frac {y(x)}{2 x}\right ) \sin \left (\frac {y(x)}{x}\right ) \cos \left (\frac {y(x)}{2 x}\right )-\frac {1}{2} y(x) \sin \left (\frac {y(x)}{x}\right )+\frac {1}{2} y(x) \sin \left (\frac {y(x)}{2 x}\right ) \cos \left (\frac {y(x)}{2 x}\right )+\frac {1}{2} y(x) \sin \left (\frac {3 y(x)}{2 x}\right ) \cos \left (\frac {y(x)}{2 x}\right )\right )}{x} \] ✓ Mathematica : cpu = 0.25737 (sec), leaf count = 20
\[\left \{\left \{y(x)\to x \sin ^{-1}\left (e^{\frac {x^2}{2}+c_1}\right )\right \}\right \}\] ✓ Maple : cpu = 0.154 (sec), leaf count = 15
\[\left \{y \left (x \right ) = x \arcsin \left (c_{1} {\mathrm e}^{\frac {x^{2}}{2}}\right )\right \}\]