Results 1 to 2 of 2

Math Help - Roots question?

  1. #1
    Junior Member
    Joined
    Jan 2008
    Posts
    53

    Roots question?

    I know you use -b/a and c/a to find the roots, but how do i know what one to use and when? For example if they ask, "the roots of 5x^2-2x+3=0" what one do i use?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Forum Admin topsquark's Avatar
    Joined
    Jan 2006
    From
    Wellsville, NY
    Posts
    9,933
    Thanks
    336
    Awards
    1
    Quote Originally Posted by eh501 View Post
    I know you use -b/a and c/a to find the roots, but how do i know what one to use and when? For example if they ask, "the roots of 5x^2-2x+3=0" what one do i use?
    If you are asking how do you solve the equation then it would be the quadratic formula:
    x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}
    not -b/a and c/a. The sum of the roots is -b/a and the product of the roots is c/a, but you can't use that to solve the equation. (At least I've never heard of anyone doing it that way.)

    -Dan
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Roots Question..
    Posted in the Pre-Calculus Forum
    Replies: 4
    Last Post: September 3rd 2010, 06:45 AM
  2. Question on roots?
    Posted in the Pre-Calculus Forum
    Replies: 6
    Last Post: February 24th 2009, 10:48 AM
  3. roots question
    Posted in the Algebra Forum
    Replies: 3
    Last Post: January 2nd 2009, 04:53 AM
  4. help with polynomial roots question
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: May 26th 2008, 08:28 AM
  5. Need Help on a roots question please!
    Posted in the Pre-Calculus Forum
    Replies: 8
    Last Post: April 9th 2008, 02:16 PM

Search Tags


/mathhelpforum @mathhelpforum