We start a new topic today. We study matrices.
In real life, we often use tables to help organize data. If we abstract the concept by extracting the data from a table and arrange them in a rows and columns with brackets, we call this rectangular array of numbers a matrix. The numbers in a matrix are called entries or elements. An element is identified by its row and column positions in the matrix. If a matrix has m rows and n columns, we say that the order of this matrix is m x n. A matrix having the same number of rows and columns is called a square matrix. For a square matrix, we can simply say its order with the number of rows.
We usually use capital letters to represent matrices.
Two matrices A and B are equal, written as A = B, if they have the same order and their corresponding elements are equal.
We then discuss the addition and subtraction of two same-order matrices.
If A and B are two matrices of the same order, then sum A+B is the matrix obtained by adding the corresponding elements in A and B.
Similarly, we define subtraction of two same-order matrices.
We talk about zero matrix where all elements are zero. It is often represented as O.
Homework:
Page 1, Page 2, Page 3, Page 4, Page 5, Page 6, Page 7, Page 8 (please keep these pages, we will need them for the next two lessons)
Workbook Page 19, #1 – #6, #12, #14, #16
Answers to last week’s homework: Answers
Note, there is no school next Sunday on 11/27. Have a nice Thanksgiving Holiday!