Question

help please i will give medals!! i will also become fan!!!!

If chelsea is trying to find the equation of a quadratic that has a focus of (1,3) and a directrix of y=-3, Describe to chelsea your preferred method for deriving the equation. make sure you use chelseas situation as a model to help her understand

Answer 1

I forgot, guys help out please!

Answer 2

It is really hard

Answer 3

Let (x,y) be a point on the parabola.
The distance between (x, y) and focus = the distance between the point and the directrix.

Answer 4

so what would that be I need the steps because that will just confuse me more!

Answer 5

Distance is
\[\sqrt{(y_2 - y_1)^2 + (x_2 - x_1)^2}\]

So for example the distance between the parabola and the focus is
\[\sqrt{(y-3)^2 + (x-1)^2}\]And the distance between the parabola and the directrix is
\[\sqrt{(y+3)^2 + 0^2}\](since it's just a line in terms of y, you can just throw out x)

Set those equal and rewrite it in standard form.

Answer 6

thank you