\[ y'(x)=\frac {\sin \left (\frac {y(x)}{x}\right ) \csc \left (\frac {y(x)}{2 x}\right ) \sec \left (\frac {y(x)}{2 x}\right ) \left (2 x^3 \sin \left (\frac {y(x)}{2 x}\right ) \cos \left (\frac {y(x)}{2 x}\right )+y(x)\right )}{2 x} \] ✓ Mathematica : cpu = 0.0652822 (sec), leaf count = 23
\[\left \{\left \{y(x)\to 2 x \cot ^{-1}\left (e^{-c_1-\frac {x^2}{2}}\right )\right \}\right \}\]
✓ Maple : cpu = 0.052 (sec), leaf count = 64
\[ \left \{ y \left ( x \right ) =\arctan \left ( 2\,{\frac {{{\rm e}^{1/2\,{x}^{2}}}{\it \_C1}}{ \left ( {{\rm e}^{1/2\,{x}^{2}}} \right ) ^{2}{{\it \_C1}}^{2}+1}},{1 \left ( - \left ( {{\rm e}^{{\frac {{x}^{2}}{2}}}} \right ) ^{2}{{\it \_C1}}^{2}+1 \right ) \left ( \left ( {{\rm e}^{{\frac {{x}^{2}}{2}}}} \right ) ^{2}{{\it \_C1}}^{2}+1 \right ) ^{-1}} \right ) x \right \} \]