Results 1 to 3 of 3

Math Help - Parabola's focus

  1. #1
    Newbie
    Joined
    May 2007
    Posts
    10

    Parabola's focus

    How can i find the focus of the parabola/arc if i know the equation
    (y= {1/125}x^2) and the distance between the endpoints (100m).
    I've looked for an explanation but i havent been able to find a good one, if someone can point to an easy to understand website that'd be great. THx
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Forum Admin topsquark's Avatar
    Joined
    Jan 2006
    From
    Wellsville, NY
    Posts
    9,857
    Thanks
    321
    Awards
    1
    Quote Originally Posted by ijleyton View Post
    How can i find the focus of the parabola/arc if i know the equation
    (y= {1/125}x^2) and the distance between the endpoints (100m).
    I've looked for an explanation but i havent been able to find a good one, if someone can point to an easy to understand website that'd be great. THx
    Ummmm...yeah! What Soroban is about to say.

    -Dan
    Last edited by topsquark; May 9th 2007 at 04:22 PM. Reason: My parabola opened the wrong way! :(
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Super Member

    Joined
    May 2006
    From
    Lexington, MA (USA)
    Posts
    11,690
    Thanks
    617
    Hello, ijleyton!

    How can i find the focus of the parabola if i know the equation: .y .= .(1/125)x

    We already know that the parabola opens upward and its vertex is the origin.

    The general form (for this parabola) is: .x .= .4py
    . . where p is the distance from the vertex to the focus.

    Your parabola is: .x .= .125y

    Hence: .4p = 125 . . . .p = 125/4

    Therefore, the focus is at: .(0, 31)

    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Focus of parabola
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: December 20th 2011, 10:46 AM
  2. Parabola and Directrix and Focus.
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: November 15th 2010, 11:19 PM
  3. [SOLVED] Parabola: co-ordinates of the focus & tangent
    Posted in the Algebra Forum
    Replies: 2
    Last Post: September 22nd 2010, 03:34 PM
  4. Parabola Finding the focus
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: January 25th 2010, 03:58 AM
  5. focus of parabola
    Posted in the Pre-Calculus Forum
    Replies: 6
    Last Post: July 6th 2006, 01:54 PM

Search Tags


/mathhelpforum @mathhelpforum