1. Direct Variation Tables and Graphs

2. 1. Cody rode his skateboard at a constant speed and then slowed down as he approached school. The story is shown on the graph. a)How fast did Cody ride his skateboard when he rode at a constant speed? b)How long did he ride at a constant speed? c)How far did he ride at his constant speed? d)What does the point (0.75, 0) mean? Find the unit rate:.

3.  Direct Variation is: A straight line Goes thru (0,0) the origin y = the same # times x y = 2x y = 3x y = ½ x

4. A table shows direct variation if: is the same for every ordered pair and the table contains the point (0, 0)

5. Determine whether or not the table models direct variation.  (0, 0) is a point in the table.  For other points calculate.  The ratio is for all points.  Yes, the table models direct variation. xyy/xy/x 00-- 12 24 36 48

6. Determine whether or not the table models direct variation.  (0, 0) is a point in the table.  For other points calculate.  The ratio is not the same for each ordered pair.  No, this table does not model direct variation. xyy/x 00-- 11 22 34 45

7. A graph shows direct variation if it is a straight line that goes through the origin.

8. Determine if each graph models Direct Variation. Explain why or why not.  Graph A: Yes, the graph is a straight line through (0, 0).  Graph B: No, the graph does not go through (0, 0).  Graph C: No, the graph is not a straight line.

9. 1. Determine whether or not the table models direct variation. 2. What are the two things needed on any direct variation graph? 3. Draw a direct variation graph. xy 00 10.5 21 31.5 42

10. Is it more challenging for you to identify direct variation in a table or on a graph? Why?

11. Target: Recognize direct variation in tables and graphs.