Results 1 to 3 of 3

Thread: Find zeros of cubic polynomial without a constant term

  1. #1
    Newbie
    Joined
    Jul 2017
    From
    USA
    Posts
    4

    Find zeros of cubic polynomial without a constant term

    Hi,

    Could someone assist with this problem.

    F(x)=5x-x^3

    Here is what I did:

    -x(x^2+5)

    I tried synthetic division using +-1, +-5, with no luck.

    Thanks.

    RB
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    16,046
    Thanks
    3621

    Re: Find zeros of cubic polynomial without a constant term

    $5x-x^3 = x(5 -x^2) = x(\sqrt{5}-x)(\sqrt{5}+x)=0 \implies x=0, \, x= \pm \sqrt{5}$
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Jul 2017
    From
    USA
    Posts
    4

    Re: Find zeros of cubic polynomial without a constant term

    Thank you very much, Skeeter!
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Find a polynomial function that has the given zeros
    Posted in the Advanced Algebra Forum
    Replies: 7
    Last Post: May 1st 2013, 08:37 PM
  2. Finding Zeros of Cubic Polynomial
    Posted in the Algebra Forum
    Replies: 5
    Last Post: Oct 26th 2012, 07:16 AM
  3. Replies: 4
    Last Post: Jan 3rd 2012, 10:45 PM
  4. Find Polynomial given zeros
    Posted in the Algebra Forum
    Replies: 6
    Last Post: Sep 28th 2007, 02:59 PM
  5. Replies: 4
    Last Post: May 2nd 2007, 08:41 AM

Search Tags


/mathhelpforum @mathhelpforum