\[ x y'(x)+\sqrt {y'(x)^2+1}-y(x)=0 \] ✓ Mathematica : cpu = 0.311398 (sec), leaf count = 119
\[\left \{\left \{y(x)\to \frac {-x \sin (2 c_1)+i x \cos (2 c_1)+2 i \sin (c_1)+2 \cos (c_1)-i x}{i \sin (2 c_1)+\cos (2 c_1)+1}\right \},\left \{y(x)\to \frac {i (i x \sin (2 c_1)+x \cos (2 c_1)-2 \sin (c_1)+2 i \cos (c_1)-x)}{i \sin (2 c_1)+\cos (2 c_1)+1}\right \}\right \}\] ✓ Maple : cpu = 0.019 (sec), leaf count = 15
\[ \left \{ y \left ( x \right ) =\sqrt {{{\it \_C1}}^{2}+1}+x{\it \_C1} \right \} \]