Question

Derive the equation of the parabola with a focus at (0, −4) and a directrix of y = 4.
f(x) = −16x2
f(x) = 16x2
f(x) = −one sixteenth x2
f(x) = one sixteenthx2

Answer 1

@satellite73 @princeharryyy

Answer 2

@pooja195

Answer 3

Ans: f(x) = (-1/16)*(x²)
D.

Answer 4

how did you get that ?

Answer 5

@WhateverYouSay

Answer 6

If the focus is at (0,-4) and the directrix is y = 4 then the vertex of the parabola is midway between these two features at (0,0).
The parabola is thus a downward opening parabola with the standard equation x² = 4cy where c is the distance from the vertex to the focus. In this question, c = -4.

Answer 7

is that the formula that you would use for all parabola equations?

Answer 8

@nono266 can you explain this better?

Answer 9

@ganeshie8

Answer 10

well it say's it's the standard equation. So i am assuming yes...

Answer 11

how do you know which one is 'C'

Answer 12

still need help!

Answer 13

??? @scenemunster

Answer 14

yes please

Answer 15

ok! from the start.

Answer 16

should we?

Answer 17

yes how do you do that?

Answer 18

The parabola can look like