Lesson 1

Lesson 1: Solving Quadratic Equations by Graphing

 

Focus

 

Major projects, such as the development of a city’s downtown business sector or the construction of a shopping district, cannot begin without plans and blueprints. In fact, large-scale projects such as these often start with an artist’s drawing of how the completed project would look. A drawing brings clarity to something that may otherwise be difficult to imagine.

 

In this lesson you will you will use the graphs of quadratic functions to “visually” determine the solutions to quadratic equations.

 

Outcomes

 

At the end of this lesson, you will be able to

• explain, using examples, the relationship among the roots of a quadratic equation, the zeros of the corresponding quadratic function, and the x-intercepts of the graph of the quadratic function
  
  
• solve a quadratic equation of the form ax2 + bx + c = 0 by graphing its corresponding function

Lesson Questions

 

You will investigate the following questions:

• How are the roots of quadratic equations related to the graphs of their corresponding quadratic functions?
  
  
• In what ways can you solve a quadratic equation by graphing?

Assessment

 

Your assessment may be based on a combination of the following tasks:

• completion of the Lesson 1 Assignment (Download the Lesson 1 Assignment and save it in your course folder now.)
  
  
• course folder submissions from Try This and Share activities
  
  
• additions to Module 4 Glossary Terms and Formula Sheet
  
  
• work under Project Connection

Self-Check activities are for your own use. You can compare your answers to suggested answers to see if you are on track. If you are having difficulty with concepts or calculations, contact your teacher.

 

Materials and Equipment

 

You will need a graphing calculator.