\[ y'(x)=\frac {x^2 \sqrt {x^2+y(x)^2}+y(x)}{x} \] ✓ Mathematica : cpu = 0.022502 (sec), leaf count = 18
\[\left \{\left \{y(x)\to x \sinh \left (c_1+\frac {x^2}{2}\right )\right \}\right \}\]
✓ Maple : cpu = 3.328 (sec), leaf count = 30
\[ \left \{ \ln \left ( \sqrt { \left ( y \left ( x \right ) \right ) ^{2}+{x}^{2}}+y \left ( x \right ) \right ) -{\frac {{x}^{2}}{2}}-\ln \left ( x \right ) -{\it \_C1}=0 \right \} \]