Ask Experts Questions for FREE Help !
Ask
    jahxx3's Avatar
    jahxx3 Posts: 4, Reputation: 1
    New Member
    		  
    #1

    Nov 22, 2010, 05:21 PM
    standard form of a parabola with a vertex and directrix
    Write the standard form of the parabola with its vertex at (0,0) at te origin and directrix x= -3
    galactus's Avatar
    galactus Posts: 2,271, Reputation: 282
    Ultra Member
    		  
    #2

    Nov 23, 2010, 05:40 AM

    Since the directrix is at x=-3, the parabola open toward the positive x-axis and has the equation



    The distance from the vertex to the directrix is the same as the distance from the vertex to the focus. P is this distance in the above equation. We can easily see that p=3.

    Plug in p=3:



    That's it.

    There are many parabola-related posts on this site. Do a search.
Not your question? Ask your question View similar questions
 

Question Tools Search this Question
Search this Question:

Advanced Search

Add your answer here.


Check out some similar questions!

Find the vertex, focus, and directrix of the parabola given by the equation. [ 1 Answers ]

(x-9)^2=-(y+8)?

Find equation of a parabola given the vertex and directrix [ 1 Answers ]

What is the equation of a parabola with a vertex at (4,8) and a directrix at y=5? I calculated the distance from the vertex to the directrix as p=3. my answer key says p=6. I cannot see were I went wrong. Can anyone provide some guidance? If p=3 is correct then the equation would be: ...

Vertex, focus, and directrix of parabola [ 2 Answers ]

How do I find the vertex, focus, and directrix of a parabola?

Find vertex, parabola, directrix of the parabola equation [ 1 Answers ]

Find the Vertex, Focus, Directrix of the parabola equation: x-(y^2)+4y-2=0

View more questions Search