\[ y''(x)=-b y(x) f(x)^{2 a}-\frac {a f'(x) y'(x)}{f(x)} \] ✗ Mathematica : cpu = 1.08347 (sec), leaf count = 0
, could not solve
DSolve[Derivative[2][y][x] == -(b*f[x]^(2*a)*y[x]) - (a*Derivative[1][f][x]*Derivative[1][y][x])/f[x], y[x], x]
✓ Maple : cpu = 0.02 (sec), leaf count = 37
\[y \relax (x ) = c_{1} {\mathrm e}^{\int i f \relax (x )^{a} \sqrt {b}d x}+c_{2} {\mathrm e}^{-\left (\int i f \relax (x )^{a} \sqrt {b}d x \right )}\]