Check out some similar questions!

bscott0890 · Jun 2, 2009, 10:40 AM

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

Unknown008 · Jun 2, 2009, 10:44 AM

Arrange your equation in this form:

$(x-h)^2=4p(y-k)$

or

$(y-k)^2=4p(x-h)$

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.

You can also search;

Parabola - Wikipedia, the free encyclopedia

Perito · Jun 2, 2009, 10:46 AM

Basically, you put your equation into a general form.

$\left(x-h^2\right)=4p\left(y-k\right) \text { axis parallel to the Y-axis}$

or

$\left(y-k^2\right)=4p\left(x-h\right) \text{ axis parallel to the X-axis}$

vertex = (h,k)
focus = (h,k + p)
directrix y = k − p. p is the distance from the vertex to the focus

Link to: Parabola - Wikipedia, the free encyclopedia