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!

Decompossing a polynomial (keep getting the wrong result )

  1. May 17, 2010 #1
    decompossing a polynomial (keep getting the wrong result :()

    1. The problem statement, all variables and given/known data

    Given the polynomial f(x) = -x^2 - x + 1, decompose the polynomial into linear terms


    3. The attempt at a solution

    I get [tex](x-(-(\frac{-\sqrt{5}+1}{2}))((x-(-\frac{-\sqrt{5}-1}{2}))[/tex]

    I seem to be missing a integer factor but can't get it to fit properly. Maybe one of you guys can point out my error ? Or where I doing this wrong :)
     
  2. jcsd
  3. May 17, 2010 #2

    gabbagabbahey

    User Avatar
    Homework Helper
    Gold Member

    Re: decompossing a polynomial (keep getting the wrong result :()

    Well, the roots of your polynomial are [tex]\frac{-1\pm\sqrt{5}}{2}[/tex], so shouldn't you have

    [tex]f(x)=-\left[x-\left(\frac{-1+\sqrt{5}}{2}\right)\right]\left[x-\left(\frac{-1-\sqrt{5}}{2}\right)\right][/tex]

    ?
     
  4. May 17, 2010 #3
    Re: decompossing a polynomial (keep getting the wrong result :()


    forgot the minus 1 I can see. Must be tired. Thanks :)
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Decompossing a polynomial (keep getting the wrong result )
Loading...