Overview:

# Part 1: Introduction to matrices

A matrix is an array of elements. The elements we will see in matrices will usually be numbers or algebraic expressions. An $$m \times n$$ matrix has $$m$$ rows and $$n$$ columns. In some books, you will find matrices written in square brackets [also known as box brackets], but here we will use round brackets (also known as parentheses). Matrices are denoted by bold, capital letters e.g. A.

The order of a matrix tells you how many rows and columns it has. Therefore, $$\begin{pmatrix} 5 & 2 & 4 \\ 1 & 8 & 2 \\\end{pmatrix}$$ is simply a $$2 \times 3$$ matrix.

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