For which values of kkk is the matrix A=(k231k001k)A = \begin{pmatrix} k & 2 & 3 \\ 1 & k & 0 \\ 0 & 1 & k \end{pmatrix}A=k102k130k singular?
k=0k = 0k=0
k=1k = 1k=1
k=−1k = -1k=−1
k=±3k = \pm\sqrt{3}k=±3