\[ x y'(x)+\sqrt {y'(x)^2+1}-y(x)=0 \] ✓ Mathematica : cpu = 0.330312 (sec), leaf count = 119
\[\left \{\left \{y(x)\to \frac {-i x+i x \cos (2 c_1)-x \sin (2 c_1)+2 \cos (c_1)+2 i \sin (c_1)}{1+\cos (2 c_1)+i \sin (2 c_1)}\right \},\left \{y(x)\to \frac {i (-x+x \cos (2 c_1)+i x \sin (2 c_1)+2 i \cos (c_1)-2 \sin (c_1))}{1+\cos (2 c_1)+i \sin (2 c_1)}\right \}\right \}\] ✓ Maple : cpu = 0.09 (sec), leaf count = 15
\[ \left \{ y \left ( x \right ) =\sqrt {{{\it \_C1}}^{2}+1}+{\it \_C1}\,x \right \} \]