X-Axis - GCSE Maths Definition

The horizontal axis on a graph is usually the x-axis. It is used to represent the independent variable (x) in the equation of the graph. The origin on a graph will be where x = 0 (and y = 0). Depending on exactly what is being shown by the graph, x may take negative values which would be to the left of the origin, positive numbers would be to the right. Together with a y-axis, the x-axis allows us to identify points in two-dimensional space. By adding a third, z-axis, we can identify points in three-dimensional space.

In GCSE Mathematics, identifying the x-axis, values on it, and their meaning, can help to quickly interpret statistical graphs or identify values for x for which a function has specific properties; for example, a turning point.