# Ellipse on x=y axis

1. Oct 28, 2008

Hi every body

I have a bounce marks on a quistion that i know nothing about

its about the Ellipse

the Qustion is

Find the standerd formula of the eelips which has foci on ( 1,1) and ( -1,-1)

and it has a major axis with 4 units.

i found that the center in at the origin and a = 2 and i didnt know anything else
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i know the ellips on x axis which has a formula of x^2-h/a^2 + y^2-k/b^2 = 1
and the ellips on the y axis which has a formula of y^2-h/a^2 + x^2-k/b^2 = 1

i know how to solve this types

but the one on the x=y axis i know nothing about it :(

can any 1 help me with this qustion or at least give me the standerd formulla of this type of ellipse :(

waiting ur helps..

2. Oct 28, 2008

### LowlyPion

Welcome to PF.

Maybe have a look here:
http://en.wikipedia.org/wiki/Ellipse#Equations

Specifically:

3. Oct 28, 2008

Last edited: Oct 28, 2008
4. Oct 28, 2008

### LowlyPion

5. Oct 29, 2008

hey man ...

englsih is not my language it is hard for me to find this thing

can u please give me the steps i should follow ???

6. Oct 29, 2008