Definition:Coordinate System/Coordinate/Element of Ordered Pair

Definition
Let $\tuple {a, b}$ be an ordered pair.

The following terminology is used:
 * $a$ is called the first coordinate
 * $b$ is called the second coordinate.

This definition is compatible with the equivalent definition in the context of Cartesian coordinate systems.

Also known as
Some authors use the terms first component and second component instead.

Also see

 * Equality of Ordered Pairs