# Ellipses

## Definition

Set of all points in a plane such that the sum of the distances from two fixed points is constant.

## Equations of Ellipses Centered at the origin.

- Standard form |(x-h)²/a² + (y-k)²/b²=1| (y-k)²/a²+(x-h)²/b²=1
- Orientation | Horizontal | Vertical
- Foci | (h+-c,k) | (h,k+-c)
- Vertices | (h+- c,k) | (h,k+-c)
- Co-Vertices |(h,k+-b) | (h+-b,k)
- Length of Major Axis| 2a units | 2a units
- Length of Minor Axis| 2b units | 2b units