Y-axis

Definition

The y-axis is one of the two primary axes in the rectangular coordinate system. It is the vertical line that runs from the bottom to the top of the coordinate plane, perpendicular to the x-axis. The y-axis is used to represent the vertical or up-and-down position of a point on the coordinate plane.

5 Must Know Facts For Your Next Test

1. The y-axis is used to represent the vertical position of a point on the coordinate plane, with positive y-values above the x-axis and negative y-values below the x-axis.
2. The y-intercept of a line is the point where the line crosses the y-axis, representing the value of y when x is zero.
3. The slope of a line is determined by the change in y-values (rise) over the change in x-values (run) between two points on the line.
4. Graphing linear inequalities involves shading the region of the coordinate plane that satisfies the inequality, with the y-axis being used to represent the vertical position of the inequality.
5. When solving systems of equations by graphing, the y-axis is used to represent the vertical position of the lines, and the point of intersection between the lines is the solution to the system.

Review Questions

• Explain the role of the y-axis in the rectangular coordinate system.
  • The y-axis is one of the two primary axes in the rectangular coordinate system, representing the vertical or up-and-down position of a point on the coordinate plane. It is perpendicular to the x-axis and is used to locate the vertical position of a point, with positive y-values above the x-axis and negative y-values below the x-axis. The y-axis is a crucial component of the coordinate system, as it allows for the precise representation and analysis of two-dimensional data.
• Describe how the y-axis is used to graph linear inequalities.
  • When graphing linear inequalities, the y-axis is used to represent the vertical position of the inequality. The region of the coordinate plane that satisfies the inequality is shaded, with the y-axis determining the vertical boundaries of the shaded area. The y-axis is essential in this process, as it allows for the visual representation of the inequality and the identification of the solutions that meet the given conditions.
• Analyze the importance of the y-axis in solving systems of equations by graphing.
  • When solving systems of equations by graphing, the y-axis is used to represent the vertical position of the lines that represent the equations. The point of intersection between the lines is the solution to the system, and the y-axis is crucial in determining the vertical coordinate of this point. The y-axis, along with the x-axis, allows for the visual representation of the equations and the identification of the point where the lines intersect, which is the solution to the system.

Related terms

Rectangular Coordinate System: A two-dimensional coordinate system that uses perpendicular x-axis and y-axis to locate points in a plane.

Intercept: The point where a line or curve intersects one of the coordinate axes.

Slope: The measure of the steepness of a line, calculated as the ratio of the change in y-values to the change in x-values between two points on the line.