Which characteristic equation has roots r1=2r_1 = 2r1=2 and r2=−2r_2 = -2r2=−2?
r2−4=0r^2 - 4 = 0r2−4=0
r2+4=0r^2 + 4 = 0r2+4=0
r2−2r+2=0r^2 - 2r + 2 = 0r2−2r+2=0
r2+2r−4=0r^2 + 2r - 4 = 0r2+2r−4=0