Final answer:
The complete characteristic equation is found by multiplying the factors (λ - r1)(λ - r2)(λ - r3)...(λ - rn) = 0, where r1 = 2 is a given root.
Step-by-step explanation:
The complete characteristic equation can be determined based on the given root r1 = 2. The characteristic equation represents the relationship between a matrix and its eigenvalues. In this case, if r1 = 2 is a root of the equation, then the complete characteristic equation can be written as (λ - r1)(λ - r2)(λ - r3)...(λ - rn) = 0, where r2, r3,..., rn are the remaining roots of the equation.