\[ \sqrt {x^2-1} y'(x)-\sqrt {y(x)^2-1}=0 \] ✓ Mathematica : cpu = 0.0520819 (sec), leaf count = 55
\[\left \{\left \{y(x)\to \frac {1}{2} \left (-e^{-c_1} \sqrt {x^2-1}+e^{c_1} \sqrt {x^2-1}+e^{-c_1} x+e^{c_1} x\right )\right \}\right \}\]
✓ Maple : cpu = 0.014 (sec), leaf count = 29
\[ \left \{ \ln \left ( x+\sqrt {{x}^{2}-1} \right ) -\ln \left ( y \left ( x \right ) +\sqrt { \left ( y \left ( x \right ) \right ) ^{2}-1} \right ) +{\it \_C1}=0 \right \} \]