g = 1000 (slider from -5 to 1000, step 0.1)
a: y = g
z = 0.15 (slider from -5 to 5, step 0.1)
P = (0, 100)
k: (z * y(P) / ((y(P) * (g - y(P)))))
f'(x, y) = ((k * y) * (g - y))
Steigungsfeld = SlopeField(f')
f = SolveODE(f', x(P), y(P), 50, 0.1)