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!

Simplify a expression

  1. Sep 25, 2005 #1
    Could someone help me to simplify this expression:



  2. jcsd
  3. Sep 25, 2005 #2


    User Avatar
    Homework Helper

    You can start by factoring out n :smile:
  4. Sep 25, 2005 #3
    I forgot to mention that it should be in the form of:

  5. Sep 25, 2005 #4


    User Avatar
    Homework Helper

    Well, n is a common factor so can you start yourself?
    After that, it'll be a bit harder to find factors but still doable (by finding zeroes of the polynomial!).

    Try factoring out n yourself ?
  6. Sep 25, 2005 #5
    thanks for the fast reply!

    I have tried to get the roots (the zeros). After taking n as a common factor we have:

    " 6n^4+15n^3+10n^2-1" has 4 roots and two of them are "strange" (dont know a better word). what i mean by strange is that one is unable to write them as 1/2, 1/3 or x/y.

    the value of the root is: -1.263763........
    the other root is: 0,263763........

    does anyone know how to deal with these kind of problems
    Last edited by a moderator: Sep 25, 2005
  7. Sep 25, 2005 #6


    User Avatar
    Homework Helper

    If a is a zero, then you can factor out (x-a)
    Try adding up all coëfficiënts of the even powers in x and the ones of the odd powers in x, if these 2 are the same then -1 is a zero and thus, (x+1) a factor.
  8. Sep 25, 2005 #7
    Thanks TD for your very fast replies

    By taking the roots i get the simplification:


    I did not understand what u mean (i have the same powers for all x (=1), or?)
    However, can i by any method cancel the 0.263763......
  9. Sep 25, 2005 #8


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Then, you should be able to divide your original polynomial by n(n+1) and see what's left.

    By the way, "strange" is irrational.
  10. Sep 25, 2005 #9
    I solved it!! :smile: :rofl: :rolleyes:

    if you multiply those irrational numbers you get a rational value!!!
    The simplified answer is

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook