Cogito
Integrated Math 3 · Chapter 8 · Lesson 1
Choosing a Function Model
Which family does the data want?
12 problems · about 21 minutes · F-LE.A.1, F-BF.A.1
Figure — use these to answer the problems
Warm Up
Straightforward practice. Get the method working first.
5 problems4, 9, 14, 19. Which family? 1 linear, 2 quadratic, 3 exponential.
AnswerWhat identifies a quadratic from a table?
- Constant second differences.
- Constant ratios.
3, 7, 11, 15. Which family? 1 linear, 2 quadratic, 3 exponential.
Answer2, 6, 18, 54. Which family? 1, 2 or 3?
Answer1, 4, 9, 16. First differences are 3, 5, 7. What is the second difference?
Answer
Build It Up
The same ideas with more to keep track of.
3 problemsDaily temperature over a year. Which family? 1 linear, 2 trigonometric.
AnswerA projectile height against time. 1 linear, 2 quadratic.
AnswerTotal cost at a fixed price per item. 1 linear, 2 exponential.
Answer
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
4 problemsMatch each pattern with the family it identifies.
Draw a line from each item on the left to its match on the right.
- Constant first differences
- Constant second differences
- Constant ratios
- Linear
- Quadratic
- Exponential
5, 10, 20, 40. Which family? 1 linear, 2 quadratic, 3 exponential.
AnswerThe Table
1, 4, 9, 16. Which family? 1 linear, 2 quadratic, 3 exponential.
AnswerThe Growth
A balance growing 5% a year. Which family? 1 linear, 2 quadratic, 3 exponential.
Answer