\[ \left (y(x)^2+1\right ) y''(x)-3 y(x) y'(x)^2=0 \] ✓ Mathematica : cpu = 0.185829 (sec), leaf count = 93
\[\left \{\left \{y(x)\to -\frac {i c_1 (x+c_2)}{\sqrt {c_1{}^2 x^2+2 c_2 c_1{}^2 x-1+c_2{}^2 c_1{}^2}}\right \},\left \{y(x)\to \frac {i c_1 (x+c_2)}{\sqrt {c_1{}^2 x^2+2 c_2 c_1{}^2 x-1+c_2{}^2 c_1{}^2}}\right \}\right \}\] ✓ Maple : cpu = 0.956 (sec), leaf count = 33
\[y \relax (x ) = \sqrt {-\frac {1}{x^{2} c_{1}^{2}+2 x c_{1} c_{2}+c_{2}^{2}-1}}\, \left (c_{1} x +c_{2}\right )\]