# Thread: conic coordinates and equations

1. ## conic coordinates and equations

I have some more problems with conics to work through....

1
What is the equation of the ellipse with foci at (0,-4) and (0,4) and the sum of its focal radii being 10?

2
Identify the following conic. that is, is it a circle, parabola, hyperbola, or ellipse? Show why.

3
Solve the system of equations.

$3x+4y+z=7$
$2y+z=3$
$-5x+3y+8z=-31$

2. At least show a little effort! For 2 you haven't even given the "following conic".

What formulas do you know for conic sections? How is the focal distance related to the lengths of the axes?

3. Originally Posted by HallsofIvy
At least show a little effort! For 2 you haven't even given the "following conic".

What formulas do you know for conic sections? How is the focal distance related to the lengths of the axes?
Heh....I'm sure I typed it in, I must have accidentally deleted it.

The conic is:
x^2-4y^2-4x-24y=48

As for conic sections, I know that an ellipse is a set of two points,called foci, that, when the sum of distances for point "P" is tabulated results in a constant.
I only know that to find an equation of a conic from the info I gave I have to use the distance formula.
I must admit to being a little lost as to how to do that though.
I think that I divide both sides of the equation by 48, but beyond that I have no idea what to do.....