Lesson 3

Lesson 3: Rational Graphs and Equations

Focus

Suppose that you need to move many tonnes of gravel and you have two trucks available. One truck is capable of completing the job in 15 trips, while the other truck is capable of completing the job in 25 trips. How could you determine the number of trips required if the two trucks drove together? This scenario can be modelled using rational functions.

In this lesson you will explore how some production and transportation problems can be solved using the graphs of rational functions.

Lesson Outcomes

At the end of this lesson you will be able to

• estimate the solutions to a rational equation by graphing
• determine extraneous roots of a rational equation

Lesson Question

You will investigate the following question:

• How can the graphs of rational functions be used to estimate solutions to a rational equation?

Assessment

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

• completion of the Lesson 3 Assignment (Download the Lesson 3 Assignment and save it in your course folder now.)
• course folder submissions from Try This and Share activities
• work under Project Connection