Results 1 to 6 of 6

Math Help - solve equation

  1. #1
    Newbie
    Joined
    Oct 2008
    Posts
    21

    solve equation

    polynomial p(x)=2x^4+5x^3-2x-5 and q(x)=x^4+x^3+2x^2+x+1 have nontrivial common divisor .solve equation p(x)=0 .

    thank you
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,698
    Thanks
    454
    only possible rational roots for q(x) are 1 and -1 ...
    Follow Math Help Forum on Facebook and Google+

  3. #3
    A riddle wrapped in an enigma
    masters's Avatar
    Joined
    Jan 2008
    From
    Big Stone Gap, Virginia
    Posts
    2,551
    Thanks
    12
    Awards
    1
    Quote Originally Posted by hoger View Post
    polynomial p(x)=2x^4+5x^3-2x-5 and q(x)=x^4+x^3+2x^2+x+1 have nontrivial common divisor .solve equation p(x)=0 .

    thank you
    p(x)=2x^4+5x^3-2x-5

    p(x)=0

    2x^4+5x^3-2x-5=0

    x^3(2x+5)-(2x+5)=0

    (2x+5)(x^3-1)=0

    (2x+5)(x-1)(x^2+x+1)=0

    ...and so on
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Newbie
    Joined
    Oct 2008
    Posts
    21
    Quote Originally Posted by skeeter View Post
    only possible rational roots for q(x) are 1 and -1 ...
    hi
    can you explain for me I dont undrestand it .
    thank uou
    Follow Math Help Forum on Facebook and Google+

  5. #5
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,698
    Thanks
    454
    Quote Originally Posted by hoger View Post
    hi
    can you explain for me I dont undrestand it .
    thank uou
    rational root theorem
    Follow Math Help Forum on Facebook and Google+

  6. #6
    A riddle wrapped in an enigma
    masters's Avatar
    Joined
    Jan 2008
    From
    Big Stone Gap, Virginia
    Posts
    2,551
    Thanks
    12
    Awards
    1
    Quote Originally Posted by hoger View Post
    hi
    can you explain for me I dont undrestand it .
    thank uou
    q(x) has no real roots.

    q(x) and p(x) share an imaginary root. You'll find that root when you solve x^2+x+1=0 from my earlier post using the quadratic formula.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. [SOLVED] Solve Differential equation for the original equation
    Posted in the Differential Equations Forum
    Replies: 5
    Last Post: February 21st 2011, 01:24 PM
  2. need to solve summation equation to solve sum(x2)
    Posted in the Statistics Forum
    Replies: 2
    Last Post: July 16th 2010, 10:29 PM
  3. How to solve this equation
    Posted in the Algebra Forum
    Replies: 4
    Last Post: December 8th 2009, 05:45 AM
  4. solve this equation for x
    Posted in the Algebra Forum
    Replies: 2
    Last Post: January 26th 2009, 04:50 AM
  5. Replies: 13
    Last Post: May 19th 2008, 08:56 AM

Search Tags


/mathhelpforum @mathhelpforum