For what value(s) of kkk is the following matrix singular (non-invertible)? A=(k23k−1)A = \begin{pmatrix} k & 2 \\ 3 & k-1 \end{pmatrix}A=(k32k−1)
k=3k = 3k=3 only
k=−2k = -2k=−2 only
k=3k = 3k=3 or k=−2k = -2k=−2
No real values of kkk make AAA singular