Extended data

A table with m rows and n columns arranged according to m × n numbers aij is called m rows and n columns matrix, or m × n matrix for short. Write down:

This number of m×n is called the element of matrix A, which is called element for short. The number aij is located in the I-th row and the J-th column of matrix A, which is called the (I, j) element of matrix A. A matrix with the number aij as the (I, j) element can be denoted as (aij) or (aij)m × n, and the m × n matrix A is also denoted as Amn.

A matrix with real elements is called a real matrix, and a matrix with complex elements is called a complex matrix. A matrix with the number of rows and columns equal to n is called an n-order matrix or an n-order square matrix.