Direct vs. indirect variation

1. Direct vs. indirect variation

2. Direct variation • A linear relationship between two variables, written in the form Y=KX or K= Huh? What this means is the Y’s will be the X’s times the same number

3. Another short cut • If Y divided by X always gives you the same number then it is direct variation. • I remember this because direct and divide by start with “D”

4. Example as table • Each X is multiplied by 3 to get the Y value

5. Example as graph

6. Example as equation • Y=3x • Y=1/2X • 2y=X because divide both sides by 2 resulting Y=1/2X

7. You try which examples are direct variation • Y=X+3 • (0,0)(1,6)(2,12) 3.

8. Inverse variation • Relationship between two variable written Y= K/x Huh, again? If Y equals a constant divided by a given X, then it is an inverse variation.

9. Another short cut • If you multiple X and Y and they always equal the same constant • then it is an inverse variation

10. Example as graph

11. Example as chart

12. You try • This time you create a chart containing an inverse variation.

13. summary