1. Graphing Points in Four Quadrants
Identify the x-axis and y-axis.
Identify the four quadrants of a coordinate plane.
Plot ordered pairs.

2. Review: Number Line
Recall that you learned about the basic number line at the beginning of the school year:
You were also introduced to zero and negatives, which completed the number line:
What if we take a second number line, turn it upright, and cross the original number line at zero?

3. Axes & Quadrants
The two number lines, when drawn like this, are called “axes”.
The horizontal number line is called the “x-axis” and the vertical number line is the “y-axis”.
The axes intersect at zero, referred to as the “origin”. They divide the plane into four sections called “quadrants”.
The quadrants are labeled with Roman numerals, starting at the positive x-axis and going around counterclockwise.

4. Good Graph vs. Bad Graph
When creating a graph on paper, it is very important that you use a ruler, even when using grid paper.
Label the x- and y-axes.

5. Graphing Points Writing coordinates Rules Tips
An ordered pair (x,y) gives the coordinates of the location of a point. The ordered pair (0,0) is the origin.
Rules
The first number is the x-coordinate; it tells you the number of horizontal units a point is from the origin.
The second number is the y-coordinate; it tells you the number of vertical units a point is from the origin.
Tips
Remember that x comes before y in the alphabet.
You walk to the elevator before you ride it up or down.

6. Follow the Signs + - + - Quadrant II (-x, y) (left, up)
Quadrant I (x, y) (right, up) - +
Quadrant III (-x, -y) (left, down)
Quadrant IV (x, -y) (right, down) -

7. Example 1
Using your ruler, draw and label the x- and y-axis. Then, plot the point A(5, 2).
Step 1: Start at the origin, where the axes intersect.
Step 2: Count to the right five units on the x-axis.

8. The point (5, 2) is in Quadrant I!
…continued
Step 3: Count up two units (parallel to the y-axis).
Step 4: Draw and label the point. A
The point (5, 2) is in Quadrant I!

9. Now You Try!
Plot the point B(4, -5) and determine in which quadrant it is located.
Plot the point C(-3, -1) and determine in which quadrant it is located.

10. Answer to #1
Step 1: Start at the origin. Step 2: Count to the right four units on the x-axis.
Step 3: Count down five
units parallel to the y-axis. Step 4: Draw and label point B. B
The point (4, -5) is in quadrant IV!

11. Answer to #2
Step 1: Start at the origin Step 2: Count to the left three units on the x-axis.
Step 3: Count down one unit Step 4: Draw and label point C.
parallel to the y-axis. C
The point (-3, -1) is in quadrant III!