Question

Find the standard form of the equation of the parabola with a focus at (-4, 0) and a directrix at x = 4.

Could someone please help?

Answer 1

Write an equation for the parabola with focus (4,0) and directrix y=2.
Thanks!
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Standard form of parabola: (x-h)^2=4p(y-k), with (h,k) being the (x,y) coordinates of the vertex
Given parabola opens downward with axis of symmetry at x=4. Vertex at (4,1). p=1


Equation of parabola:
(x-4)^2=-4(y-1) (ans)
see the graph below as a visual check on the answer
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y=1-(x-4)^2/4

Answer 2

I'm so confused I'm sorry @wintersuntime

Answer 3

Are you trying to graph it ?

Answer 4

And it's okay I love helping others

Answer 5

No. These are the answer I am given:
A. y^2 = -8x
B. 16y = x^2
C. y = -1/16x^2
D. x = -1/16y^2

Answer 6

What do you think the answer will be ?

Answer 7

I am thinking C. @wintersuntime

Answer 8

why ?

Answer 9

Honestly, I'm not sure. I just thought that standard form looked most similar to that choice. @wintersuntime

Answer 10

its not C

Answer 11

Could you explain how to find the correct answer then? I am so lost. @saseal