2.123   ODE No. 123

\[ x y'(x)-y(x)-x \sin \left (\frac {y(x)}{x}\right )=0 \] Mathematica : cpu = 0.127073 (sec), leaf count = 19


\[\left \{\left \{y(x)\to 2 x \cot ^{-1}\left (\frac {e^{-c_1}}{x}\right )\right \}\right \}\] Maple : cpu = 0.081 (sec), leaf count = 44


\[y \relax (x ) = \arctan \left (\frac {2 x c_{1}}{x^{2} c_{1}^{2}+1}, \frac {-x^{2} c_{1}^{2}+1}{x^{2} c_{1}^{2}+1}\right ) x\]