# X-Coordinates (Mathematics Glossary)

# What Is the X-Coordinate?

The x-coordinate is the first number in the pair of numbers used to describe Cartesian coordinates.For example, in the Cartesian coordinates

**(2,4)**, the x-coordinate is

**2**(the number on the left):

# What Does the X-Coordinate Mean?

The x-coordinate tells you how far**across**the horizontal x-axis a point is on a graph (measured from the origin).

If a point has Cartesian coordinates

**(2,4)**, the point would be

**2**units along the x-axis. The image below shows what we mean by a point being 2 units along the x-axis (measured from the origin):

**Note:**The x-axis is labelled with numbers (0, 1, 2, 3...) so you can measure how far across the point is.

# The X-Coordinate Can be Positive...

If you go**right**along the x-axis (starting at the origin, where it crosses the y-axis), it is labelled with positive numbers (0, 1, 2, 3...).

The x-coordinate of any point to the

**right**of the y-axis is

**positive**.

Imagine a point had an x-coordinate of

**4**. It would be

**4**units to the

**right**of the y-axis:

# ...Or the X-Coordinate Can be Negative

If you go**left**along the x-axis (starting at the origin, where it crosses the y-axis), it is labelled with negative numbers (0, -1, -2, -3...).

The x-coordinate of any point to the

**left**of the y-axis is

**negative**.

Imagine a point had an x-coordinate of

**-4**. It would be

**4**units to the

**left**of the y-axis:

##### Interactive Test

**show**

Here's a second test on the x-coordinate.

Here's a third test on the x-coordinate.

# Which Axis Is Which?

The**x is a cross**- so the

**x-axis goes across**!

The y-axis must go up.

##### Note

# The Origin

The point labelled with a 0 on the x-axis is called the origin.# What Are Cartesian Coordinates?

Cartesian coordinates are used to describe the position of a point on a graph.Cartesian coordinates work by measuring how far across and how far up the point is from the origin.