\[ y'(x)=\frac {\csc \left (\frac {y(x)}{2 x}\right ) \sec \left (\frac {y(x)}{2 x}\right ) \sec \left (\frac {y(x)}{x}\right ) \left (x^2 \sin \left (\frac {y(x)}{2 x}\right ) \sin \left (\frac {y(x)}{x}\right ) \cos \left (\frac {y(x)}{2 x}\right )-\frac {1}{2} y(x) \sin \left (\frac {y(x)}{x}\right )+\frac {1}{2} y(x) \sin \left (\frac {y(x)}{2 x}\right ) \cos \left (\frac {y(x)}{2 x}\right )+\frac {1}{2} y(x) \sin \left (\frac {3 y(x)}{2 x}\right ) \cos \left (\frac {y(x)}{2 x}\right )\right )}{x} \] ✓ Mathematica : cpu = 0.0371157 (sec), leaf count = 14
\[\left \{\left \{y(x)\to x \sin ^{-1}\left (e^{c_1+x}\right )\right \}\right \}\]
✓ Maple : cpu = 0.049 (sec), leaf count = 16
\[ \left \{ y \left ( x \right ) ={\frac {\arccos \left ( \left ( {{\rm e}^{x}} \right ) ^{2}{\it \_C1}+1 \right ) x}{2}} \right \} \]