Matrices — O/L Mathematics

A matrix is a rectangular arrangement of numbers (or other mathematical objects) enclosed in square brackets. These numbers are called entries or elements. Matrices are fundamental tools for organizing data, solving systems of linear equations, and representing transformations in geometry. In Grade 11, we focus on 2x2 and 2x1 matrices, and their basic operations.

Order of a Matrix: The order (or size) of a matrix is given by the number of rows (horizontal lines) followed by the number of columns (vertical lines). It is written as "rows × columns". For example, a matrix with 2 rows and 2 columns is a 2 × 2 matrix. A matrix with 2 rows and 1 column is a 2 × 1 matrix (also called a column vector).

Notation: Matrices are usually denoted by capital letters like A, B, M, etc. A general 2 × 2 matrix is written as:

A = [ a b ]

[ c d ]

Here, a, b, c, d are the entries. The entry in the first row and first column is a, first row second column is b, second row first column is c, and second row second column is d.