A quesion on establishment of nature of roots

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Discussion Overview

The discussion revolves around proving that the only root of the equation x5 + x = 10 is irrational. Participants are exploring methods to demonstrate this, including the use of the Rational Root Theorem and considerations of the nature of the root's decimal expansion.

Discussion Character

  • Homework-related
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant suggests using the Rational Root Theorem to find a contradiction that the root cannot be rational.
  • Another participant expresses uncertainty about how to derive a contradiction, noting that assuming a rational root in p/q form does not lead to a clear conclusion.
  • A later reply mentions that the root must be a non-terminating, non-repeating decimal expansion, but does not provide a method to prove this.
  • Participants reference a link that outlines a procedure related to the Rational Zero Theorem, indicating that it describes all possible rational roots of the equation.

Areas of Agreement / Disagreement

Participants do not reach a consensus on how to prove the irrationality of the root, with multiple approaches and uncertainties expressed throughout the discussion.

Contextual Notes

There are limitations in the assumptions made regarding the nature of the roots and the application of the Rational Root Theorem, which may not fully address the problem at hand.

Akshay_Anti
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we are given an equation x5+x=10
. How to prove that the only root for the equation is irrational? I'm an average 12th standard student. So, please keep it low. Thanks in advance.
 
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Did you try using the Rational root Theorem?

It's quite clear that there is only one real root to the equation. If you can find a contradiction that the root cannot be rational, you are done :smile:
 
How to contradict? Assuming a p/q form doesn't help... the root must be of form non- terminating non-repeating decimal expansion... how to do that?
 
Akshay_Anti said:
How to contradict? Assuming a p/q form doesn't help... the root must be of form non- terminating non-repeating decimal expansion... how to do that?

The link Infinitum posted outlines the procedure. The rational zero theorem clearly describes all possible rational roots of the equation.
 

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