We have our midterm exam. Test result will be emailed to each family.

## Math 9, Lesson 8, Spring 2019, 4/7/2019

## Math 9, Lesson 7, Spring 2019, 3/31/2019

We have a review day today. We will have midterm exam next week.

Students should review their homework.

## Math 9, Lesson 6, Spring 2019, 3/24/2019

We focus on speed-time graphs, how to read a speed-time graph, how to calculate the distance, how to draw a distance-time graph from a speed-graph, etc.

We will have a review class next time. We will have our mid exam on 4/7.

Here are some more homework:

Page 7, Page 8, Page 9, Page 10, Page 11

#18, #19, #20, #22, #23, #24, #25.

## Math 9, Lesson 5, Spring 2019, 3/17/2019

## Math 9, Lesson 4, Spring 2019, 3/10/2019

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

## Math 9, Spring 2019, Lesson 3, 3/3/2019

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

## Math 9, Lesson 2, Spring 2019, 2/10/2019

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.

## Math 9, Spring 2019, Lesson 1, 2/3/2019

We start the new chapter on vectors.

While a scalor is a quantity that has only magnitude, a vector is a quantity that has both magnitude and direction. We usually use directed line segment to represent a vector. The direction of the line segment, indicated by an arrow, represents the direction of the vector, and the length of the line segment represents the magnitude of the vector.

Two vectors are equal if they have equal magnitude and are in the same direction.

For vector additions, we study the triangle law and parallelogram law of vector additions.

Homework:

Page 1, Page 2, Page 3, Page 4

Workbook P 31, #1, #2, #3, #4, #5, #12, #15.

## AoPS Algebra 2B, Lesson 16, Fall 2018, 1/27/2019

We wrap up this semester (and this school year) by going over some more problems with floor functions, as well as talking about recursive sequences.

## Math 9, Lesson 16, Fall 2018, 1/27/2019

Today we have our final exam. I will email the test result to each family soon.

Next week we will start Spring 2019 semester and teach the 2nd half of Math 9.