Given matrix A=(2112)A = \begin{pmatrix} 2 & 1 \\ 1 & 2 \end{pmatrix}A=(2112) with eigenvalue λ=3\lambda = 3λ=3, which vector is an eigenvector?
(11)\begin{pmatrix} 1 \\ 1 \end{pmatrix}(11)
(1−1)\begin{pmatrix} 1 \\ -1 \end{pmatrix}(1−1)
(23)\begin{pmatrix} 2 \\ 3 \end{pmatrix}(23)
(01)\begin{pmatrix} 0 \\ 1 \end{pmatrix}(01)