X-Axis Definition: a plain-English explanation of what the term means, why it matters in math, and how it is used, followed by worked examples and practice questions so the definition turns into something you can apply.
Math Dictionary / X-Axis
X-Axis
The x-axis is the horizontal number line on the coordinate plane.
GeometryGrade 5Grade 6Grade 7Grade 8Algebra 1GEDSATACT
What it means
It helps locate the x-coordinate of a point.
Also called: horizontal axis
Examples
| The x-axis runs left and right |
| Points on the x-axis have y = 0 |
| The origin lies on the x-axis |
Common mistake
The x-axis is horizontal; the y-axis is vertical.
Try one
Question: What is the y-coordinate of any point on the x-axis?
Show answer
It is 0.