X-Axis

Definition

The x-axis is the horizontal reference line in a rectangular coordinate system that represents the independent variable. It is used to measure the position or value of an object along the horizontal dimension.

5 Must Know Facts For Your Next Test

1. The x-axis is the horizontal axis that runs left to right on a coordinate plane, representing the independent variable.
2. The position of a point on the x-axis is measured by its distance from the origin (0, 0), which is the intersection of the x-axis and y-axis.
3. When graphing linear equations, the x-axis is used to plot the independent variable, which is typically the input value or the variable that can be controlled.
4. The x-intercept of a linear equation is the point where the graph of the equation intersects the x-axis, indicating the value of x when y = 0.
5. The slope of a linear equation is the ratio of the change in the y-value (vertical change) to the change in the x-value (horizontal change), which is represented by the coefficient of x in the equation.

Review Questions

• Explain the role of the x-axis in the rectangular coordinate system and how it relates to graphing linear equations.
  • In the rectangular coordinate system, the x-axis is the horizontal reference line that represents the independent variable. When graphing linear equations, the x-axis is used to plot the independent variable, which is typically the input value or the variable that can be controlled. The position of a point on the x-axis is measured by its distance from the origin (0, 0), which is the intersection of the x-axis and y-axis. The x-intercept of a linear equation is the point where the graph of the equation intersects the x-axis, indicating the value of x when y = 0.
• Describe how the x-axis is used to determine the slope of a linear equation.
  • The slope of a linear equation is the ratio of the change in the y-value (vertical change) to the change in the x-value (horizontal change), which is represented by the coefficient of x in the equation. To determine the slope, you need to identify two points on the graph of the linear equation and calculate the rise (change in y-value) over the run (change in x-value) between those two points. The x-axis is used to measure the horizontal change in the x-value, which is the denominator of the slope formula.
• Analyze the relationship between the x-axis, the independent variable, and the graphing of linear equations.
  • The x-axis in the rectangular coordinate system represents the independent variable, which is the input value that can be controlled or manipulated. When graphing linear equations, the x-axis is used to plot the independent variable, while the y-axis represents the dependent variable, which changes in response to the independent variable. The position of points on the x-axis determines the x-coordinate of the graph, which, along with the y-coordinate, defines the location of the points that satisfy the linear equation. The x-intercept of the graph, where the line intersects the x-axis, indicates the value of the independent variable (x) when the dependent variable (y) is equal to zero.

Related terms

Rectangular Coordinate System: A two-dimensional coordinate system that uses perpendicular horizontal and vertical axes, known as the x-axis and y-axis, to locate points in a plane.

Graphing Linear Equations: The process of representing linear equations, which have the form $y = mx + b$, on a coordinate plane by plotting points that satisfy the equation.

Dependent and Independent Variables: In a linear equation, the independent variable (x) is the input value that can be controlled or manipulated, while the dependent variable (y) is the output value that changes in response to the independent variable.