SECTION 5 – 4 WRITING A FUNCTION RULE

Objective:To write a function rule given a table or a real-world situation

Example 1 Writing a Rule from a Table

Write a function rule for each table.A) “What can I do to 1 to get 5, to 2 to get

6, …?”

Write a function rule for each table.B) “What can I do to 1 to get 1, to 3 to get

9, …?”

Think-Pair-Share

Write a function rule for each table.1) 2)

Example 2 Real-World P.S.A) A carpenter buys finishing nails by the pound. Each pound of nails costs $1.19. Write a function rule to describe this relationship.

How much do 12 lb. of finishing nails cost?

B) The yearbook club makes $25 per page of advertising in the yearbook. Write a function rule to describe this relationship.

The class sold 6 pages of advertising. How much money did the class make?

Example 3 Real-World P.S.A) Suppose you borrow money from a relative to buy a lawn mower that costs $245. You charge $18 to mow a lawn. Write a rule to describe your profit as a function of the number of lawns mowed (m).

B) The choir spent $100 producing audio tapes of tis last performance and will sell the tapes for $5.50 each. Write a rule to describe the choir’s profit as a function of the number of tapes sold (t).