For an=6an−1−9an−2a_n = 6a_{n-1} - 9a_{n-2}an=6an−1−9an−2, the characteristic equation is r2−6r+9=0r^2 - 6r + 9 = 0r2−6r+9=0. What type of roots?
Two distinct real roots
One repeated real root
Two complex conjugate roots
One positive and one negative root