What is the characteristic polynomial of A=(2103)A = \begin{pmatrix} 2 & 1 \\ 0 & 3 \end{pmatrix}A=(2013)?
(λ−2)(λ−3)(\lambda - 2)(\lambda - 3)(λ−2)(λ−3)
(λ+2)(λ+3)(\lambda + 2)(\lambda + 3)(λ+2)(λ+3)
λ2+5\lambda^2 + 5λ2+5
λ2−1\lambda^2 - 1λ2−1