Find the eigenvalues of the matrix A=[2112]A = \begin{bmatrix} 2 & 1 \\ 1 & 2 \end{bmatrix}A=[2112]
λ=1,3\lambda = 1, 3λ=1,3
λ=2,2\lambda = 2, 2λ=2,2
λ=0,4\lambda = 0, 4λ=0,4
λ=−1,5\lambda = -1, 5λ=−1,5