Square Matrix/Examples/Real 2 x 2

Example of Square Matrix

A $2 \times 2$ real square matrix is an array of $4$ real numbers $p, q, r, s$ arranged as:

$\quad \mathbf A = \begin {bmatrix} p & q \\ r & s \end {bmatrix}$

Sources

• 1969: C.R.J. Clapham: Introduction to Abstract Algebra ... (previous) ... (next): Chapter $1$: Integral Domains: $\S 3$. Definition of an Integral Domain: Example $3$