What is the characteristic equation for an=3an−2a_n = 3a_{n-2}an=3an−2?
r2−3=0r^2 - 3 = 0r2−3=0
r2+3=0r^2 + 3 = 0r2+3=0
r−3=0r - 3 = 0r−3=0
r2−3r=0r^2 - 3r = 0r2−3r=0