ax^2 + bx+c =0
discriminant b^2-4ac
(-6)^2 - 4(1) *(9)
36-36 = 0
if the discriminant >0 it has 2 real roots
= 0 it has 1 root of multiplicity 2
< 0 has 2 imaginary root
x^2 - 6x + 9 = 0
(x-3)(x-3)=0
root is 3 multiplicity 2
Answer : double root real and rational