Results 1 to 3 of 3

Math Help - For what value of K..

  1. #1
    Member
    Joined
    Sep 2006
    Posts
    75

    For what value of K..

    For what value of K does the equation 2x^2-Kx+8=0 have equal roots?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,663
    Thanks
    1616
    Awards
    1
    We must have b^2 - 4ac =0. So what is k?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by ceasar_19134 View Post
    For what value of K does the equation 2x^2-Kx+8=0 have equal roots?
    The roots may be found from the quadratic formula:

    x = (K +/- sqrt(K^2-64))/4

    These roots are equal when the discriminant (the stuff under the square root)
    is zero. So the value/s of K you seek is/are the solution/s of:

    K^2-64 = 0

    RonL
    Follow Math Help Forum on Facebook and Google+


/mathhelpforum @mathhelpforum