For which value of kkk does the system Ax=0Ax = 0Ax=0 have a non-trivial solution if A=(1k24)A = \begin{pmatrix} 1 & k \\ 2 & 4 \end{pmatrix}A=(12k4)?
k=1k = 1k=1
k=2k = 2k=2
k=0k = 0k=0
k=4k = 4k=4