\[ x y'(x) \left (y(x) \sin \left (\frac {y(x)}{x}\right )-x \cos \left (\frac {y(x)}{x}\right )\right )-y(x) \left (y(x) \sin \left (\frac {y(x)}{x}\right )+x \cos \left (\frac {y(x)}{x}\right )\right )=0 \] ✓ Mathematica : cpu = 0.423044 (sec), leaf count = 31
\[\text {Solve}\left [-\log \left (\frac {y(x)}{x}\right )-\log \left (\cos \left (\frac {y(x)}{x}\right )\right )=2 \log (x)+c_1,y(x)\right ]\] ✓ Maple : cpu = 0.086 (sec), leaf count = 23
\[ \left \{ y \left ( x \right ) ={\frac {{\it \_C1}}{\cos \left ( {\it RootOf} \left ( -{\it \_Z}\,\cos \left ( {\it \_Z} \right ) {x}^{2}+{\it \_C1} \right ) \right ) x}} \right \} \]