Question

What is the equation of the parabola that has a vertex of (3, 6) and a focus of (3, 8)?

A) y - 6 = 1/8(x - 3)^2
B) y - 3 = 1/4(x - 6)^2
C) y - 6 = 4(x - 3)^2
D) y - 3 = 8(x - 6)^2

Answer 1

So the form y – k = a(x – h)^2 I believe. (h,k) is the vertex and you figure out to which side of the vertex is the focus. Haven't done this in awhile

Answer 2

That equation tells you which ones you can eliminate. Then use 4p(y – k) = (x – h)^2 to find p. Your p should be 2, the distance between the focus and the vertex.

Answer 3

>.< So then what do you do with p?

Answer 4

You just wanna see which equation has p=2 which corresponds to the parabola you're given

Answer 5

So how do I find which equation has p=2?

Answer 6

You rearrange the equations into the form 4p(y – k) = (x – h)^2

Answer 7

And there isn't an easier way to figure it out? >.>

Answer 8

(x - h)^2 = 4p(y - k)
where the vertex is (h,k) and p = distance from vertex to to focus... :|

Answer 9

just put the values in it :|

Answer 10

So is the answer A?

Answer 11

vertex = (3, 6)
focus = (3, 8)
here focus is about the vertex so p will be positive
p= 2 (by distance formula)
(x - 3)^2 = 4(2)(y - 6)
(x - 3)^2 = 8(y - 6)

Answer 12

=>1/8(x - 3)^2 = (y - 6)

Answer 13

yup A

Answer 14

Okie dokie. Thanks

Answer 15

:3 welcome fluffy

Answer 16

xD fluffy?

Answer 17

yup your new name *-*

Answer 18

Haha ok :P