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Lesson 6

1. Lesson 6

1.5. Explore

Mathematics 20-2 M5 Lesson 6

Module 5: Radicals

 
Explore
 
This is a picture of a collision between a car and a transit bus.

© swisshippo/32497251/Fotolia

You were able to determine that if the driver was going 50 km/h, the skid marks should be 20 m long. What if, however, the driver had been going a different speed that didn’t show up in the table of values you created? If you could just rearrange the equation to solve for d and substitute in the value for s, you could easily determine the correct skid mark length at any given speed.

 

Try This 2
 

The Radical Equations: Tutorial applet will help you discover how to solve equations that have variables under the radical sign. You may be required to enter a username and a password. Then, choose “Radical Equations.” At the new page, select the tutorial icon: it is the icon at the top of the page that is shaped like a blackboard. This will take you to a tutorial menu page. Work through the five tutorial pieces.

 

This is a screenshot for Radical Equations: Tutorial.


textbook

Read “Example 1: Using inverse operations to solve radical equations” on pages 216 to 218 of your textbook. Look closely at the process used to determine the solutions. How important is it that you verify your answer by substituting back into the original equation?

Self-Check 1

  1. extraneous root: a root, which is also called a solution, that appears to be a solution to an equation but does not satisfy the conditions that were originally introduced

    What restrictions are there on the values of the variables in each of the following equations if the equations involve real numbers? Solve and check each of the equations to make sure there are no extraneous roots.
    1. Explain why there is an extraneous root in this instance.




    Answers

textbook
  1. Complete “Check Your Understanding” question 3 and “Practising” questions 4 and 5 on page 222 of your textbook. Answers