\[ \left (x^2+1\right ) y'(x)^2-2 x y(x) y'(x)+y(x)^2-1=0 \] ✓ Mathematica : cpu = 0.0385488 (sec), leaf count = 45
\[\left \{\left \{y(x)\to c_1 x-\sqrt {1-c_1{}^2}\right \},\left \{y(x)\to c_1 x+\sqrt {1-c_1{}^2}\right \}\right \}\] ✓ Maple : cpu = 0.052 (sec), leaf count = 57
\[y \relax (x ) = \sqrt {x^{2}+1}\]