Results 1 to 3 of 3

Math Help - proving roots irrational

  1. #1
    Newbie
    Joined
    Oct 2008
    Posts
    2

    proving roots irrational

    My class was given an assignment of proving the roots of 3, 6, and 12 as irrational. I have solved 3 and 6, and tried using what I did there for 12, but it is not working out. Someone help me out please?
    Here is the prob:
    If n^2=12, then n is not rational.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member flyingsquirrel's Avatar
    Joined
    Apr 2008
    Posts
    802
    Hi,

    If you know that \sqrt{3} is an irrational number then you can use this : \sqrt{12}=\sqrt{4\times3}=2 \sqrt{3}\ldots
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Oct 2008
    Posts
    2
    wow... i have no idea why i kept overlooking that... i would always get to p^2=3q^2 (sorry, i am still tryin to learn how to much the computer math stuff) and i was so tryin to use the common factor that i didnt even notice what i was arriving at, thanks so much
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Irrational Roots
    Posted in the Advanced Algebra Forum
    Replies: 3
    Last Post: April 5th 2010, 06:29 AM
  2. please help irrational roots of polynomials
    Posted in the Algebra Forum
    Replies: 1
    Last Post: November 13th 2008, 06:39 PM
  3. Proving something is irrational
    Posted in the Number Theory Forum
    Replies: 1
    Last Post: October 28th 2008, 05:21 PM
  4. Proving something irrational
    Posted in the Discrete Math Forum
    Replies: 2
    Last Post: October 28th 2008, 07:27 AM
  5. Proving irrational
    Posted in the Number Theory Forum
    Replies: 4
    Last Post: September 25th 2008, 01:12 PM

Search Tags


/mathhelpforum @mathhelpforum