対角行列
[ 1 0 0 2 ] {\displaystyle {\begin{bmatrix}1&0\\0&2\\\end{bmatrix}}}
[ 1 0 0 0 0 10 0 0 0 0 − 8 0 0 0 0 7 ] {\displaystyle {\begin{bmatrix}1&0&0&0\\0&10&0&0\\0&0&-8&0\\0&0&0&7\end{bmatrix}}}