Results 1 to 2 of 2

Math Help - Quadratics

  1. #1
    Senior Member
    Joined
    Jul 2008
    Posts
    347

    Unhappy Quadratics

    Hi

    I was just wondering if anyone could please help me with this question:

    Find the values of k for which the equation x^2 + 16x - 4k = 0 has the roots differing by 6.

    I tried doing: Let the roots be a and a - 6 but that obviously doesn't get me any close to the answer.

    Please, any help?

    Thanx
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by xwrathbringerx View Post
    Hi

    I was just wondering if anyone could please help me with this question:

    Find the values of k for which the equation x^2 + 16x - 4k = 0 has the roots differing by 6.

    I tried doing: Let the roots be a and a - 6 but that obviously doesn't get me any close to the answer.

    Please, any help?

    Thanx
    Use the quadratic formula to get the solutions in terms of k. After simplifying you get:

    x = 8 + 2 \sqrt{16+k} and x = 8 - 2 \sqrt{16+k}.

    Take the difference: 4 \sqrt{16 + k}.

    Equate the difference to 6 and solve for k.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. quadratics help
    Posted in the Pre-Calculus Forum
    Replies: 4
    Last Post: February 24th 2009, 03:38 PM
  2. Quadratics
    Posted in the Algebra Forum
    Replies: 6
    Last Post: December 8th 2008, 01:39 AM
  3. Quadratics
    Posted in the Algebra Forum
    Replies: 8
    Last Post: November 2nd 2008, 05:58 AM
  4. Help with Quadratics
    Posted in the Algebra Forum
    Replies: 2
    Last Post: June 19th 2008, 08:09 PM
  5. Quadratics, Help!
    Posted in the Math Topics Forum
    Replies: 1
    Last Post: June 17th 2008, 04:37 PM

Search Tags


/mathhelpforum @mathhelpforum