For which value of λ\lambdaλ does the system (A−λI)x=0(A - \lambda I)x = 0(A−λI)x=0 have a non-trivial solution, where A=(2112)A = \begin{pmatrix} 2 & 1 \\ 1 & 2 \end{pmatrix}A=(2112)?
λ=2,2\lambda = 2, 2λ=2,2
λ=0,4\lambda = 0, 4λ=0,4
λ=−1,1\lambda = -1, 1λ=−1,1
λ=1,3\lambda = 1, 3λ=1,3