F'(t) = \frac(100)(t^2 + 4) - 100t(2t)(t^2 + 4)^2 = \frac100(t^2 + 4 - 2t^2)(t^2 + 4)^2 = \frac100(4 - t^2)(t^2 + 4)^2. - Nelissen Grade advocaten