Given A=(2102)A = \begin{pmatrix} 2 & 1 \\ 0 & 2 \end{pmatrix}A=(2012), calculate A2−4AA^2 - 4AA2−4A.
(0100)\begin{pmatrix} 0 & 1 \\ 0 & 0 \end{pmatrix}(0010)
(−400−4)\begin{pmatrix} -4 & 0 \\ 0 & -4 \end{pmatrix}(−400−4)
(4404)\begin{pmatrix} 4 & 4 \\ 0 & 4 \end{pmatrix}(4044)
(0000)\begin{pmatrix} 0 & 0 \\ 0 & 0 \end{pmatrix}(0000)