This document provides an overview of matrices, including how they are named, the elements within them, and how their dimensions are written. It explains that matrices are arrays of numbers, with elements designated by their row and column position. Square matrices have the same number of rows and columns, while non-square matrices have different numbers of rows and columns. Examples are provided to demonstrate finding specific elements and their locations within matrices of various sizes.

1. Notes

2. Matrices are named with capital letters. Each number in a matrix is an element of that matrix. In matrix A, a 11 = the element in row 1, column 1 a 21 = the element in row 2, column 1 a 12 = the element in row 1, column 2 a 22 = the element in row 2, column 2 The dimension of a matrix are written as #x#. # rows x # columns Matrix A is a 2x2 (read “2 by 2”) A square matrix means the number of rows equals the number of columns. Matrix A is a square matrix because it is a 2x2. Other square matrices are 3x3, 4x4, 5x5, and so on. ***2x4 is NOT a square matrix A matrix is just an array of numbers. Matrices is the plural form of matrix

3. Example: What is the element in b 21 ? What is the location of 0? -5 b 12 This is a 3x3 matrix.

4. In matrix C, What is the element in c 23 What is the element in c 32 What is the location of 1 What is the location of -3 b 33 b 13 -9 13

5. Try these: What are the dimensions of the following matrices? 3x1 1x3 3x4 3x2