Question

Find the standard form of the equation of the parabola with a focus at (0, -9) and a directrix y = 9.
explain how to do this please?

Answer 1

@deepconcept did your face fall asleep on the keyboard lol

Answer 2

let a arbitrary point P (x,y) on parabola.
from definition of parabola, distance of point P (x,y) from focus S (0, -9) is equal to its distance from directrix.(say MN)
then, SP= perpendicular distance of P from MN....
proceed now.....

Answer 3

i'm confused @deepconcept

Answer 4

can you walk me through this?

Answer 5

(y-9)^2 = (x-0)^2 + (y+9)^2

Answer 6

solving , we get x^2 = -36y

Answer 7

and to solve for y we get y=-x^2/36?

Answer 8

it's not the standard form of parabola.

Answer 9

well that's my answer choice..

Answer 10

all my answer choices are solved for either y or y^2..

Answer 11

have you got the answer?