1. Lesson 1

1.7. Explore 3

Mathematics 20-1 Module 6

Module 6: Rational Expressions

 

Non-Permissible Values

 

A rational expression is not defined when the expression’s denominator is zero. Therefore, any value of the variable that would result in a denominator of zero is considered a non-permissible value.

 

Try This 2

 

For each of the rational expressions in the table, determine the non-permissible value(s). You can check your answers by using your calculator.

 

 
Rational Expression Non-Permissible Value(s) of x
 
 
 
 

 

course folder Save your response in your course folder.


textbook
This cartoon shows that a zero is not allowed to enter a denominator club. The zero is allowed to enter the numerator club..

Turn to “Example 1” on page 312 in the textbook to see how you can determine non-permissible values for rational expressions that are similar to the expressions in Try This 2. Look for answers to the following questions:

  • What equations are used to find non-permissible values?
  • Why is it not necessary to determine when numerators are equal to zero?
  • How does factoring the denominator make it easier to identify non-permissible values?

Look back at your answers to Try This 2. After reading through “Example 1,” are there any answers you would change? Why?

 

Self-Check 1

 

Complete Non-Permissible Values Self-Check to check your understanding of the concepts presented so far.

 

 
This is a play button that opens Non-Permissible Values Self-Check.