1. Trendlines & Excel

2. Same Log In Press: Control-Alt-Delete Username: physics Password: success

3. Same Example Experiment How big will your goldfish be if you fed it 7.5 pellets per day? ?

4. Use Your Old Data food (pellets/day)mass (g) 16 28 313 415 525 634 752 878 994 10121 After 6 months…

5. Do Over: Enter Your Data Row 1: Names Row 2: Date Row 3: Blank Row 4: Headings Row… : Data

6. Graph It Again Ingredients: Meaningful Title Labeled Axis Units in Parentheses White Background No Gridlines

7. Mathematical Relationships (Trend Lines) Have Excel draw lines through your data. Pick the “best fit” line. Excel gives you the equation. Use the equation to make a prediction. Ex: Calculate the goldfish’s mass if it is fed 7.5 food pellets per day.

8. Example: Add a “Best Fit” Trend Line to our Goldfish Growth Graph Goldfish Graph Next: You add a best fit trend line to the examples.

9. Linear Relationship Use a straight line. Mathematically: The dependent variable (y) does the same thing as your independent variable (x).

10. Inverse Relationship Excel calls this a Power function Mathematically: exponent = -1 ← makes this an inverse Your dependent variable (y) does the opposite of your independent variable (x)

11. Quadratic Relationship Excel calls this a Polynomial function Order = 2 ← this makes it a quadratic Mathematically:

12. Notes:

13. Your Turn Enter your data for the heights and stopping distances you measured yesterday.

14. Your Turn Find the best fit trend line. Use the equation to predict how far it would take your cart to stop if released from 65 cm.

15. Print & Save Save on your floppy disk or it will be lost forever.