2-5 writing a function rule

1. 2-5 writing a function rule Miss battaglia – algebra 1 cp Objective: Write rules for functions from tables and words.

2. Warm up • If you wrote the integers 1 to 100, how many times would you write the digit 3?

3. Function notation To write a rule in function notation, you use the symbol f(x) in place of y. f(x) = 2x - 5 input values independent variable output values dependent variable

4. example Find f(-2), f(0), and f(7) for f(x) = 2x - 5

5. Write a function rule for each table. Find f(7) for both functions

6. example • Identify the independent variable and the dependent variable for the table. • Let the independent variable be x and the dependent variable be f(x). Write a function for the table.

7. Using words to write a rule • In a Computer Museum, the exhibit is about 20 times larger than a normal-sized desktop computer. Write a function rule to describe the relationship.

8. example • Suppose you borrow money from a relative to buy a lawn mower that costs $245. You charge $18 to mow an average-size yard. Write a rule to describe your profit as a function of the number of lawns mowed. Find f(9)

9. homeWork • Pg81 # 1-12