This preview shows page 1. Sign up to view the full content.
Unformatted text preview: this case.
The next step is to determine where both the numerator and the denominator are zero. In this
case these values are. numerator : x = -1 denominator : x = 5 Now, we need these numbers for a couple of reasons. First, just like with polynomial
inequalities these are the only numbers where the rational expression may change sign. So, we’ll
build a number line using these points to define ranges out of which to pick test points just like
we did with polynomial inequalities.
There is another reason for needing the value of x that make the denominator zero however. No
matter what else is going on here we do have a rational expression and that means we need to
avoid division by zero and so knowing where the denominator is zero will give us the values of x
to avoid for this.
Here is the number line for this inequality.
© 2007 Paul Dawkins 135 http://tutorial.math.lamar.edu/terms.aspx College Algebra So, we need regions that make the rational expression negative. That means the middle region.
Also, since we’ve got an “or equal to” part in the inequality we also need to include w...
View Full Document
This note was uploaded on 06/06/2012 for the course ICT 4 taught by Professor Mrvinh during the Spring '12 term at Hanoi University of Technology.
- Spring '12