axis | One of two perpendicular lines of a coordinate place that intersect at the origin. The plural form of axis is axes. |
boundary line | A line that divides the coordinate plane into two regions. If points along the boundary line are included in the solution set, then a solid line is used; if points along the boundary line are not included then a dotted line is used. |
coordinate plane | A plane formed by the intersection of a horizontal number line called the x-axis and a vertical number line called the y-axis. |
linear equation | An equation in two variables whose ordered pairs graph as a straight line. |
linear inequality | A mathematical statement in two variables using the inequality symbols <, >, ≤, or ≥ to show the relationship between two expressions. When the inequality symbol is replaced by an equal sign, the resulting related equation will graph as a straight line. |
linear relationship | A linear relationship exists between two variables if, when you plot their values on a coordinate system, you get a straight line. |
ordered pair | A pair of numbers that indicates a point on a coordinate plane. |
origin | The point where the x-axis and the y-axis intersect on the coordinate plane (0, 0). |
parallel lines | Two or more lines that lie in the same plane but which never intersect. |
perpendicular lines | Two lines that lie in the same plane and intersect at a 90º angle. |
quadrant | The x- and y-axes divide the coordinate plane into four regions. These regions are called quadrants. |
rise | The vertical change between two points on a line. |
run | The horizontal change between two points on a line. |
slope | The ratio of the vertical change to the horizontal change of two points on a line. |
slope-intercept form | A linear equation written in the form y = mx + b, where m represents the slope of the line, and b represents the y-value of the y-intercept, (0, b). |
x-axis | The horizontal axis of a coordinate plane. Also the horizontal axis of a bar graph or histogram. |
x-coordinate | The first number in an ordered pair, which tells the distance to the right or left from the origin when graphing in a coordinate plane. |
x-intercept | The point where the graph of a linear equation intersects the x-axis (x, 0). |
y-axis | The vertical axis of a coordinate plane. Also the vertical axis of a bar graph or histogram. |
y-coordinate | The second number in an ordered pair, which tells the distance to move up or down from the origin when graphing in a coordinate plane. |
y-intercept | The point where the graph of a linear equation intersects the y-axis (0, y). |