\[ y'(x)-f(x) (y(x)-g(x)) \sqrt {(y(x)-a) (y(x)-b)}=0 \] ✗ Mathematica : cpu = 3.03356 (sec), leaf count = 0 , could not solve
DSolve[-(f[x]*Sqrt[(-a + y[x])*(-b + y[x])]*(-g[x] + y[x])) + Derivative[1][y][x] == 0, y[x], x]
✗ Maple : cpu = 0. (sec), leaf count = 0 , could not solve
dsolve(diff(y(x),x)-f(x)*(y(x)-g(x))*((y(x)-a)*(y(x)-b))^(1/2) = 0,y(x))