In reference to the question that goes as follows: "Given that (lambda)=2 is a root of the characteristic equation of the process: Xn = (11/6)*Xn-1 - Xn-2 + (1/6)*Xn-3 + en calculate the other roots and classify the process as I(d)." The solution states that "it is easy to see that differencing the process once will eliminate the root of 1". Can someone please explain me how this is done?
