Math 20-2

Chapter 7 Quadratic Equations

Lesson 7.1   Solving Quadratic Equations by Graphing

GOAL

The goal of this lesson is stated at the top of page 396 in your textbook, and is also written below.
Keep this in mind as you work through the lesson material.

Solve quadratic equations by graphing the corresponding function.

Explore...

Try to answer the question in the sidebar on page 396.

Watch

Video Tutorial

Investigate the Math

Investigate an idea or problem, with a partner if possible.
The investigation provides the background for the ideas presented in the lesson.

TEXT Pages 396 - 397

Read/Work through the Investigate section on Pages 396-397 in your textbook.

Go through this material,  AS BEST YOU CAN,  before you view the video tutorials that follow.

Demonstration

Solve[-4.9(t^2)+68t==0, t]

?  How can you determine the times during the flight when the rocket will be at Sasha’s eye level?

Be sure to work through the investigation as best as you can, before you watch the video!!

Video Tutorial

Apply the Math  (Examples)

Examples will give you TOOLS for solving problems, and also show you that there may be different ways to approach a question.

YOUR TURN gives YOU the chance to try to do a problem ON YOUR OWN,  using the examples as models.

Example 1  Verifying solutions to a quadratic equation

TEXT Pages 397 - 398

Work through Example 1 on Pages 397 - 398 in your textbook.

Watch

Video Tutorial

Your Turn

Use the Video Tutorial for help, or to check your work, BUT... you should do your best to do this question ON YOUR OWN FIRST!

Video Tutorial

Example 2  Graphing to determine the number of roots

TEXT Pages 399 - 400

Work through Example 2 on Pages 399 - 400 in your textbook.

Watch

Video Tutorial

Your Turn

Use the Video Tutorial for help, or to check your work, BUT... you should do your best to do this question ON YOUR OWN FIRST!

The roots of an equation are equivalent to the x-intercepts of the corresponding function.
A quadratic function can have at MOST two intercepts.

Example 3  Solving a quadratic equation in non-standard form

TEXT Page 401

Work through Example 3 on Page 401 in your textbook.

Watch

Video Tutorial

Your Turn

Use the Video Tutorial for help, or to check your work, BUT... you should do your best to do this question ON YOUR OWN FIRST!

I answered this when I did Example 3.

In Summary

Key Ideas and Need to Know 
Presents and summarizes  the main new concepts of the lesson

•	Carefully read through each of the bullet points in this section.

•	If you are unclear about any of these ideas,  ASK YOUR TEACHER FOR HELP!

Practice Problems

Doing Practice Problems

Practice problems reinforce the math presented in this lesson.

•	Work through the practice problems for this lesson.
	These problems are for practice, you don’t need to hand them in!
	(your teacher may assign specific questions for you to complete)

•	Use the answers in the back of the book to CHECK YOUR WORK!

•	If you make a mistake, TRY TO FIX IT!

•	If you need help or want more information, view the video solutions provided.

•	If you still need more help,  CONTACT YOUR TEACHER!

Types of Practice Problems

Check Your Understanding questions require basic understanding of the ideas of the  lesson.

Practising questions will require you to dig deeper for a solution.

Closing  A summary question that often asks YOU to explain ideas in your own words.

Extending questions offer enrichment and extension.

Question 7

Notes

Question 6,    I didn’t do a video for this one.
You can check the answers in the back of the book, the method has been illustrated many times.

Question 7,    You can experiment with the demonstration above if it helps with visualizing the question.

Question 15,    Here is the link to the Desmos page I used for this question

Video Solution Links

Check your work for every problem you do!
If you make a mistake,  try to fix it!
Use the video solutions for more information.
If a problem still doesn’t make sense, ASK YOUR TEACHER FOR HELP!

({{"Question 1", "Question 2", "Question 3", "Question 4", "Question 5"}, { , "Question 7", "Question 8", "Question 9", "Question 10"}, {"Question 11", "Question 12", "Question 13", "Question 14", "Question 15"}})