son 1.5 NAME Coordinate Systems, Ordered Pairs, and Relations A coordinate plane is formed by two intersecting number lines. The horizontal line is called the x-axis. The vertical line is called the y-axis. This two-axis system is called the coordinate system. The coordinates of a point are represented by the ordered pair (x, y). This shows the distance the point is from the origin (0, 0), in the domain (the set of x coordinates) and the range (the set of y coordinates). A set of ordered pairs is called a relation. In the graph at right, Point A is located at (4, 2). Point B is located at (-5,-3). Quadrant 1 B 34 Quads When two ordered pairs differ only by signs, the locations of the points are related by reflections across one or both axes. The coordinates of Point C differ from the coordinates of Point B by only the sign of the x-coordinate. So Point C, located at 15, -3), is a reflection of Point B across the y-axis. Write the ordered pair for each lettered point on the grid. I. A Y B 2. C D 3. G H