We have a review day today. We will have our midterm exact next time.

## Math 9, Lesson 7, 3/23/2023

## Math 9, Lesson 6, 3/16/2023

More Complex Number workout.

## Math 9, Lesson 5, 3/9/2023

We go back to Complex Number and study more. This is because the test results from the final exam shows that students do not fully get it. So we will be taking the next two lessons to go over it again.

## Lesson 4 Homework Answers

Complete answers for the last week’s homework

## Math 9, Lesson 4, 3/2/2023

We go over the application of vectors, particularly in geometry.

Notice when vector AB = vector DC, it means line AB is parallel to line DC and AB = DC.

If you have not done your homework last week because you have some questions on certain problems, please do them now:

Homework: Page 1, Page 2, Page 3, Page 4, Page 5, Page 6

Workbook Page 33: # 8, #9, #13, #19 – #26

## Lesson 3 Homework Answers

## Math 9, Lesson 3, 2/16/2023

We continue our study of vectors.

We can simplify the position of a point P on a plane by the vector OP where O is a reference point on the plane. The vector OP is called the position vector of P with respect to the reference point O. That is, every point on the plane can be represented by its position vector wrt the reference point O.

Then vector PQ = vector OQ – vector OP.

Furthermore, when we look at the coordinate plane for a point P (x, y), we can use its coordinates x and y to represent its position vector with respect to the origin O. We introduce column vector notation. A column vector is like a special form of a matrix (2 rows, 1 column). All matrix operations apply to column vectors.

We can apply what we have learned about vectors to help us solve geometry problems.

Notice when vector AB = vector DC, it means line AB is parallel to line DC and AB = DC.

Homework: Page 1, Page 2, Page 3, Page 4, Page 5, Page 6

Workbook Page 33: # 8, #9, #13, #19 – #26

Answers to last homework: answers

## Math 9, Lesson 2, 2/9/2023

For a given vector **a**, a vector which has the same magnitude but in the opposite direction of a is called the negative of vector **a** , and is denoted by –**a**.

The subtraction of a vector **v** from a vector **u** can be denoted as adding the vector –**v** to **u**: **u** – **v** = **u** + (-**v**).

A vector with the same initial point and the terminal point has zero magnitude. It is called a zero vector, or a null vector, and is denoted by **0**. **a** + (-**a**) = **a** – **a** = **0**.

When a vector **a** is multiplied by a constant k, the product k**a** is called a scalar multiplication of** a** and is defined as follows:

* If k > 0, k**a** is a vector with magnitude k|**a**| and in the same direction as **a**;

* If k < 0, k**a** is a vector with magnitude -k|**a**| and in the opposite direction of **a**;

* If k = 0, k**a** is a zero vector **0**.

Homework: Page 1, Page 2, Page 3, Page 4, Page 5

Workbook Page 33, #6, #7, #10, #11, #14 – #18, #20, #21.

## Lesson 2 Homework Answers

Answers to last homework: answers

## Lesson 1 Homework Answers

You can find the answers to last homework here: answers