# Y-Coordinates (Mathematics Glossary)

# What Is the Y-Coordinate?

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

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

**4**(the number on the right):

# What Does the Y-Coordinate Mean?

The y-coordinate tells you how far**up**(or

**down**) the vertical y-axis a point is on a graph (measured from the origin).

If a point has Cartesian coordinates

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

**4**units up the y-axis. The image below shows what we mean by a point being 4 units along the x-axis (measured from the origin):

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

# The Y-Coordinate Can be Positive...

If you go**up**the y-axis (above the x-axis), it is labelled with positive numbers (0, 1, 2, 3...).

The y-coordinate of any point

**above**the x-axis is

**positive**.

Imagine a point had an y-coordinate of

**4**. It would be

**4**units

**above**the y-axis:

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

If you go**down**the y-axis (below the x-axis), it is labelled with negative numbers (0, -1, -2, -3...).

The y-coordinate of any point

**below**the x-axis is

**negative**.

Imagine a point had an y-coordinate of

**-4**. It would be

**4**units

**below**the x-axis:

##### Interactive Test

**show**

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

Here's a third test on the y-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 y-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.