# introduction to matrice

Consider the information given below in the post-primary football tournament last season in Kampala district.

The result for three schools, Kakungulu Memorial School, Kibuli SS, and St Peter’s SS were as shown below.

The above information can shortly be written as

The numbers above are arranged in a rectangular form. Such an arrangement of numbers is what is known as matrix.

Definition
A matrix is arrays of numbers in rectangular form with large brackets around them.

OR:
A matrix is a collection of information (numbers) stored in rows and columns.

Common terms used

Below are some of the frequently used terms:

1. Entry (an element)
This is a number within the matrix. At times it is known as component. Consider the matrix below.

The numbers: 2, 3, 4 and 5 are the elements of the above matrix.

Rows of a matrix

2. These are the lines of numbers that goes across the page. Considering the above matrix i.e.

(2 3) forms the first row and (4 5) forms another row. Therefore, the matrix above has two rows.

3. Columns of a matrix

These are the lines of numbers that go down the page. Considering

above matrix has two columns also.

NB:
A matrix is represented with upper case letters. In identifying matrix, one has to use the position of row and colomn for example

Then;

a is element of 1st row and 1st column

b is element of 1st row and 2nd column

c is element of 2nd row and 1st column

d is element of 2nd row and 2nd column.

1. Order of a matrix
This refers to the number of rows and columns in a given matrix and it is given by = Order X Row Column Consider the matrix below:

The matrix above has 2 rows and 2 columns. Therefore the order of the above matrix above is 2 2.

Example

State the order of the following given matrices.

NB:
The number of rows is denoted by m and column by n. When stating the order of the matrix, the number of rows is

written (stated) first. This is followed by the number of columns, i.e.

Order = m x n