Question

What is the focal width of (-1/12)x^2=y?

Answer 1

what's a focal width?

Answer 2

length of a vertical or horizontal line that
passes through the focus and touches the parabola on each end

Answer 3

it says |4a|

Answer 4

4a?

Answer 5

I don't know what it means that's why I asked lol

Answer 6

heh, I mean, I know what you're saying, I was looking for a good graphic :)

Answer 7

nevermind the 4a that was an example i thought it was like an equation for focal width

Answer 8

but is not 4a as far as I know

Answer 9

one sec

Answer 10

okay! :)

Answer 11

i think it's either 48 or 12

Answer 12

12

Answer 13

the "c" or so-called focal point is \(c =\cfrac{1}{4a} \)

Answer 14

like the (h,k+a) in the picture http://www.boredofstudies.org/wiki/images/6/6f/Parabola.png

Answer 15

so, from \(y = -\cfrac{1}{12} x^2\)

the "a" component would be coefficient of "x"

Answer 16

so is 12 a?

Answer 17

or is a 3?

Answer 18

I'm confused lol

Answer 19

well, you have a negative \(-\frac{1}{12}\) that'd give you a -3

Answer 20

oh true but if c=1/4a then wouldn't c=1/12??

Answer 21

with a negative lol

Answer 22

yes

Answer 23

but the only possible choices are 12 and 48