For comparison, Newton's theorem of revolving orbits corresponds to the case a = 1 and b = 0, so that r 1 = r 2. In this case, the original force is not scaled, and its argument is unchanged; the inverse-cube force is added, but the inverse-square term is not. Also, the path of the second particle is r 2 = g (θ 2 / k), consistent with the formula given above.