1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Easy question about the root (of a real number)

  1. Oct 23, 2009 #1
    [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:
    [tex]\sqrt{3 - 2\sqrt{2}} = \sqrt{2} - 1[/tex]

    Last edited: Oct 23, 2009
  2. jcsd
  3. Oct 23, 2009 #2
    [tex]\sqrt{3 - 2\sqrt{2}}=\sqrt{2-2\sqrt{2}+1}[/tex]

    what is the relationship between [tex]\left(2-2\sqrt{2}+1\right)[/tex] and [tex]\left(\sqrt{2} - 1\right)[/tex]??
  4. Oct 23, 2009 #3
    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


    and solve it as is (this will ultimately lead you to what S_David is pointing out).
  5. Oct 23, 2009 #4
    OK! Got it !
    Sorry for wasting your time and thank you !! :)

    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: Oct 23, 2009
  6. Oct 23, 2009 #5
    Definitely didn't waste my time. You forced me to think, which is always good! :biggrin:
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook