Ask Me Help Desk

Ask Me Help Desk (https://www.askmehelpdesk.com/forum.php)
-   Math & Sciences (https://www.askmehelpdesk.com/forumdisplay.php?f=402)
-   -   Learning how to write an equation for a parabola. (https://www.askmehelpdesk.com/showthread.php?t=354089)

  • May 15, 2009, 02:16 AM
    ashlyn sims
    learning how to write an equation for a parabola.
    I need like step through step ways to write an equation for a parabola.

    So like here are two examples we can use:

    Focus(1,4) Diretrix:y=2


    Focus(-2,-6) Latus Rectum=8
  • May 15, 2009, 05:11 AM
    Perito
    Quote:

    I need like step through step ways to write an equation for a parabola.

    So like here are two examples we can use:

    Focus(1,4) Directrix: y=2

    Focus(-2,-6) Latus Rectum=8
    There's a lot of information about parabolas here:

    Parabola - Wikipedia, the free encyclopedia

    The basic equations for parabolas are

    (parabola's axis parallel to y-axis)

    or

    (parabola's axis parallel to x-axis)

    The vertex is (x,k); the focus is (h, k+p); the directrix is y=k-p where p is the distance from the vertex to the focus.

    In your first case, you have Focus(1,4) Directrix: y=2

    h = 1
    k+p=4
    k-p=2
    so k=3 and p=1

    From the directrix, y=2, the parabola's axis is parallel to the y-axis.

    (parabola's axis parallel to y-axis)



    You can multiply it out



    You should work on the second problem. The Wikipedia article has information on it.
  • Dec 12, 2009, 02:35 PM
    kumar94
    I don't understand how to do this question:A parabola has vertex 0,0 and focus on coordinate axis. Write equation of parabola if; a) the focus is; 1) 4, 0 2)-6, 0 3)0, 3. The directrix is the line defined by y=8
  • Dec 13, 2009, 08:52 AM
    InfoJunkie4Life

    Kumar, you can start your own thread in order to have help with your question.

  • All times are GMT -7. The time now is 12:35 AM.