Читать книгу SAT Math For Dummies with Online Practice - Mark Zegarelli - Страница 70

Every point on the xy-plane is labeled uniquely as a pair of coordinate points, or coordinates, of the form . The coordinates of the origin are .

Starting from the origin, you can find the coordinates of any point by counting first on the x-axis, and then on the y-axis. This is called plotting a point.

Figure 2-3 shows you how to plot four points on the xy-plane.

FIGURE 2-3: Plotting four points on the xy-plane: , , , and .