\[ -y(x) f'(x)+2 f(x) y'(x)+2 f(x) y(x)^2-2 f(x)^2=0 \] ✓ Mathematica : cpu = 0.163848 (sec), leaf count = 39
\[\left \{\left \{y(x)\to i \sqrt {f(x)} \tan \left (i \int _1^x-\sqrt {f(K[1])}dK[1]+c_1\right )\right \}\right \}\] ✓ Maple : cpu = 0.052 (sec), leaf count = 23
\[\left \{y \left (x \right ) = i \sqrt {f \left (x \right )}\, \tan \left (c_{1}-i \left (\int \sqrt {f \left (x \right )}d x \right )\right )\right \}\]