Find the characteristic polynomial of the matrix A=(4102)A = \begin{pmatrix} 4 & 1 \\ 0 & 2 \end{pmatrix}A=(4012).
λ2−6λ+8\lambda^2 - 6\lambda + 8λ2−6λ+8
λ2−6λ+4\lambda^2 - 6\lambda + 4λ2−6λ+4
λ2−2λ+8\lambda^2 - 2\lambda + 8λ2−2λ+8
λ2+6λ−8\lambda^2 + 6\lambda - 8λ2+6λ−8