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:

Workbook Page 19, #1 – #6, #12, #14, #16

Note, there is no school next Sunday on 11/29. Have a nice Thanksgiving Holiday!

We went over the midterm exam first, then did a review on equations and inequalities.

We looked at linear equations, system of linear equations, quadratic equations, rational equations, and linear inequalities.

For homework, use the sheets below:

#2 – #18.

Page 1, Page 2, Page 3

Today is a review day, as we will have our midterm exam next time on 11/8. We go over what we have learned this semester so far.

There is no specific homework, but the student should go back to the old class notes and homework to prepare for the exam.