Let $A$ and $B$ be two $2 \times 2$ upper triangular matrices. This means they can be written as:
\[ A = \begin{bmatrix} a & b \\ 0 & c \end{bmatrix} \]
\[ B = \begin{bmatrix} x & y \\ 0 & z \end{bmatrix} \]
where $a, b, c, x, y, z$ are elements in some field
Show more…