# Kampyle of Eudoxus

## Curve

The **Kampyle of Eudoxus** has the Cartesian equation:

- $x^4 = x^2 + y^2$

where the point $x = y = 0$ is specifically excluded.

In polar coordinates, it is described by the equation:

- $r = \sec^2 \theta$

## Source of Name

This entry was named for Eudoxus of Cnidus.

He used it in his work relating to the problem of Doubling the Cube.

The word **kampyle** comes from the Greek **καμπύλη** (pronounced *kam- pill-ee*), meaning

**curve**.