How to Rationalize the Denominator of a Radical Expression?

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Homework Help Overview

The discussion revolves around the problem of rationalizing the denominator of a radical expression involving cube roots. The original poster presents a specific expression to be rationalized, indicating a focus on algebraic manipulation and properties of radicals.

Discussion Character

  • Exploratory, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants explore the use of algebraic identities, specifically the sum of cubes, to approach the problem. There is a mention of a specific algebraic form and attempts to apply it to the given expression. Some participants question the relevance of certain algebraic identities to the original problem.

Discussion Status

The discussion includes various attempts to rationalize the denominator, with some participants providing algebraic identities as potential tools. However, there is no explicit consensus on the best approach, and the original poster expresses uncertainty about the next steps in their solution process.

Contextual Notes

Participants note the complexity of the problem and the challenges in applying certain algebraic identities. The original poster's attempt at a solution indicates a struggle with the rationalization process, and there is a lack of complete information on how to proceed effectively.

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Homework Statement


Rationalize the denominator..
[tex] \frac{1}{\sqrt[3]{a}+\sqrt[3]{b}+\sqrt[3]{c}}[/tex]


Homework Equations



Algebraic equations.

The Attempt at a Solution


So using the form
a3 + b3 + c3 - 3abc= (a + b + c)(a2 + b2 + c2 - ab - bc - ca)

So it becomes


[tex] \frac{\sqrt[3]{a^2}+\sqrt[3]{b^2}+\sqrt[3]{c^2} -\sqrt[3]{ab}-\sqrt[3]{bc}-\sqrt[3]{ca} }{a + b + c - 3 \sqrt[3]{abc}}[/tex]


Actually I don't know what to do next
If i try (a+b)(a-b) then it doesn't work out ...
 
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Use

[tex]x^3-y^3=(x-y)(x^2+xy+y^2)[/tex]

ehild
 


ehild said:
Use

[tex]x^3-y^3=(x-y)(x^2+xy+y^2)[/tex]

ehild
I don't see how this applies to the OP's problem.
 


ehild said:
Use

[tex]x^3-y^3=(x-y)(x^2+xy+y^2)[/tex]

ehild

Mark44 said:
I don't see how this applies to the OP's problem.

[tex]x-y=\frac{x^3-y^3}{x^2+xy+y^2}[/tex]

:wink:
 


Good thing you put in the wink emoticon.
 


Of course! An emoticon is worth a thousands words.

If there were a more suitable emoticon for "I'm sure you get it now" I would use that one instead.

:smile: << (don't kill me for this :-p)
 


Yup got it!
Thanks!

(Checked it out with my teacher ... its right!)
 

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