Easy question about the root (of a real number)

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Discussion Overview

The discussion revolves around the mathematical expression \(\sqrt{3 - 2\sqrt{2}}\) and its equivalence to \(\sqrt{2} - 1\). Participants explore methods to demonstrate this relationship, focusing on algebraic manipulation and reasoning.

Discussion Character

  • Exploratory
  • Mathematical reasoning
  • Homework-related

Main Points Raised

  • One participant expresses embarrassment in asking how to prove \(\sqrt{3 - 2\sqrt{2}} = \sqrt{2} - 1\).
  • Another participant suggests rewriting \(\sqrt{3 - 2\sqrt{2}}\) as \(\sqrt{2 - 2\sqrt{2} + 1}\) and questions the relationship between this expression and \(\sqrt{2} - 1\).
  • A participant notes that solving the equation directly may provide insight into the relationship, referencing a previous comment by another user.
  • One participant acknowledges the need for clever thinking to understand the solution and emphasizes the importance of 'seeing' the answer.
  • Another participant expresses satisfaction in having understood the solution and thanks others for their contributions.

Areas of Agreement / Disagreement

Participants generally agree on the need for clever reasoning to solve the problem, but the discussion does not reach a consensus on a specific method or approach to demonstrate the equivalence.

Contextual Notes

Some participants reference the need for insight or a particular perspective to understand the solution, indicating that the problem may not be straightforward for everyone.

joris_pixie
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[SOLVED] Easy question about the root (of a real number)

Hi, I'm a bit embarresed to ask this but does anybody know how to get this:
\sqrt{3 - 2\sqrt{2}} = \sqrt{2} - 1

?
 
Last edited:
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joris_pixie said:
Hi, I'm a bit embarresed to ask this but does anybody know how to get this:
\sqrt{3 - 2\sqrt{2}} = \sqrt{2} - 1

?
\sqrt{3 - 2\sqrt{2}}=\sqrt{2-2\sqrt{2}+1}

what is the relationship between \left(2-2\sqrt{2}+1\right) and \left(\sqrt{2} - 1\right)??
 
I must say that this one does require a bit of clever thinking. I can add that the best way to "see" the answer is to take your equation

\sqrt{3-2\sqrt{2}}=\sqrt{2}-1

and solve it as is (this will ultimately lead you to what S_David is pointing out).
 
OK! Got it !
Sorry for wasting your time and thank you ! :)

phyzmatix said:
This one does require a bit of clever thinking I must say. I can add that the best way to "see" the answer is to take your equation

\sqrt{3-2\sqrt{2}}=\sqrt{2}-1

and solve it as is (this will ultimately lead you to what S_David is pointing out).

It's true that it is one you have to 'see' !
And if you 'see it' it's easy, but if you don't ...

But thanks a lot you guys, got it now!
 
Last edited:
joris_pixie said:
OK! Got it !
Sorry for wasting your time and thank you ! :)

Definitely didn't waste my time. You forced me to think, which is always good! :biggrin:
 

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