GMAS review (Identifying and evaluating functions)

Three relations are shown in the image. Which of these relations is a function?

• A only

• A, B and C

• A and B only

• B only

• B and C only

• -216

• 3

• 4

• 6

• -26

• -31

• 12

• -8

A theatre group charges $12.50 for its opening play of the season. Production costs for the play are $150. Formulate a function that could be used to determine the profit that theatre group earns from selling x tickets.

Verizon charges $35 a month as a flat fee plus $0.28 for every phone call made. Formulate a function that models a phone bill as a function of phone usage.