| − | The '''X-axis''' is the horizontal axis on a coordinate plane, as opposed to the vertical axis, or [[y-axis]]. The point at which a line crosses the x-axis is referred to as the [[x-intercept]]. | + | The '''X-axis''' is the horizontal axis on a coordinate plane, as opposed to the vertical axis, or [[y-axis]]. The point at which a line crosses the x-axis is referred to as the [[x-intercept]]. The [[y-intercept]] is defined as infinity. |