Rationalizing Denominators: Understanding the Process

  • Thread starter majormuss
  • Start date
In summary, the conversation discusses the use of x^2 instead of x^3 to rationalize the denominator in a given equation. It is explained that in order to rationalize the fifth root, the numerator and denominator must be multiplied by the appropriate power of x.
  • #1
majormuss
124
4

Homework Statement



I am confused with this equation I found online... It seems wrong to me, I need help.
My question is,why did the person who worked taht equation use a x^2 to rationalize the equation when the actual equation was an x^3??
http://tutorial.math.lamar.edu/Classes/Alg/Radicals_files/eq0081MP.gif

Homework Equations





The Attempt at a Solution

 
Physics news on Phys.org
  • #2
Because the fifth root of x^2*x^3=x^5 is x. How would you do it??
 
  • #3
Dick said:
Because the fifth root of x^2*x^3=x^5 is x. How would you do it??

no my question is... why was x^2 used instead of x^3 to rationalize the denominator? my thinking is if x^2 is the denominator then why use x^3 to rationalize it?
 
  • #4
Because [itex]x^2*x^3= x^5[/itex] as Dick said. The crucial point is that it is the fifth root that is to be rationalized. You have to multiply what ever power is necessary to get a fifth power inside the fifth root.

In general to rationalize the denominator of [itex]1/\sqrt[n]{x^m}[/itex] you need to multiply numerator and denominator by [itex]\sqrt[n]{x^{n-m}}[/itex]. That way, in the denominator you will have [itex]\sqrt[n]{x^nx^{n-m}}= \sqrt[n]{x^n}= x[/itex].
 
  • #5
HallsofIvy said:
Because [itex]x^2*x^3= x^5[/itex] as Dick said. The crucial point is that it is the fifth root that is to be rationalized. You have to multiply what ever power is necessary to get a fifth power inside the fifth root.

In general to rationalize the denominator of [itex]1/\sqrt[n]{x^m}[/itex] you need to multiply numerator and denominator by [itex]\sqrt[n]{x^{n-m}}[/itex]. That way, in the denominator you will have [itex]\sqrt[n]{x^nx^{n-m}}= \sqrt[n]{x^n}= x[/itex].

I get it now thanks..
 

What is "rationalizing the denominator"?

"Rationalizing the denominator" is a mathematical process used to remove any square roots or imaginary numbers in the denominator of a fraction. This is done by multiplying both the numerator and denominator by a suitable rational number.

Why is it necessary to rationalize the denominator?

Rationalizing the denominator is necessary because it allows us to simplify fractions and make them easier to work with. It also helps us to compare and perform operations on fractions more accurately.

How do you rationalize the denominator?

To rationalize the denominator, you can multiply the fraction by a rational number that has the same square root in the numerator and denominator. Another method is to use the conjugate of the denominator, which is the same expression but with the opposite sign.

Is rationalizing the denominator always necessary?

No, rationalizing the denominator is not always necessary. It is usually done to make the expression simpler, but sometimes it is not needed for calculations.

Can you rationalize any denominator?

Yes, any denominator can be rationalized, but the method used may vary depending on the expression. For example, some denominators may require multiple steps to rationalize, while others can be done in one step.

Similar threads

  • Precalculus Mathematics Homework Help
Replies
3
Views
2K
  • Precalculus Mathematics Homework Help
Replies
5
Views
2K
  • Precalculus Mathematics Homework Help
Replies
2
Views
2K
  • Precalculus Mathematics Homework Help
Replies
14
Views
2K
  • Precalculus Mathematics Homework Help
Replies
6
Views
1K
  • Precalculus Mathematics Homework Help
Replies
2
Views
1K
  • Precalculus Mathematics Homework Help
Replies
4
Views
2K
  • Precalculus Mathematics Homework Help
Replies
12
Views
2K
  • Precalculus Mathematics Homework Help
Replies
1
Views
959
  • Precalculus Mathematics Homework Help
Replies
6
Views
3K
Back
Top