Graphing Points in the Plane

You can graph points the same way that Sam found the fly. Let's practice graphing different points in the plane.

Try the Chameleon Graphing Java Applet

We'll begin by graphing point (0, 0).

Sam starts at the origin and moves 0 units along the x-axis, then 0 units up. He has found (0,0) without going anywhere!

Sam marks the point with a green dot, and labels it with its coordinates.

Sam has finished graphing point (0, 0).

Next, let's graph point (0, 3).

Sam starts at the origin, just like always. He moves 0 units along the x-axis, because the x-coordinate of the point he is trying to graph is 0.

Sam uses his tongue to move a green dot 3 units straight up.

The final step is labeling the point.

Notice that point (0, 3) is on the y-axis and its x-coordinate is 0. Every point on the y-axis has an x-coordinate of 0, because you don't need to move sideways to reach these points. Similarly, every point on the x-axis has a y-coordinate of 0.

Let's end with a more complicated example: graphing point (2, -2).

Sam begins at point (0, 0).

He moves 2 units along the x-axis.

The y-coordinate of the point Sam wants to graph is -2. Because the number is negative, Sam sticks his tongue down two units. This makes sense, because negative numbers are the opposite of positive numbers, and down is the opposite of up.

Before he leaves, Sam labels the point he graphed.

Try the Chameleon Graphing Java Applet