Functions and Writing Functions

Write the following in function notation. A doctor measured a patient’s resting pulse rate at 80 beats per minute.

• f(x) = 80y

• f(y) = 80y

• f(x)=80x

Function: f(x) = 55x + 11

What is the answer if the independent variable is 3?

• 66

• 121

• 176

Write the following in function notation.

A Pizza restaurant offers the following deal $8.99 for on large pizza and $5 for each additional large pizza on the same order

• f(x) = 8.99x + 5

• f(x) = 5x + 8.99

• f(x) = 5x - 8.99

How would you write y = 2x - 3 in function notation?

• y = 2x-3

• f = 2x - 3

• f(x) = 2x-3

Which of the following represents a function?

Which of the following is the correct definition of a function?

• A relation where each input has exactly one output

• A relation where each input has multiple outputs

• A relation where each output has multiple inputs

• A relation where inputs and outputs are the same

A taxi company charges a flat fee of $3 plus $2 per mile driven. Write the function that represents the total cost (C) as a function of the number of miles driven (m). Then, interpret the rate of change and the initial value.

• C(m) = 2m + 3

• C(m) = 3m + 2

• C(m) = 4m + 1

• C(m) = 5m + 2

The amount of cola in a soda machine decreases by a rate of 5% each hour. The amount of cola in the machine was originally 75 gallons. Which function models the amount of cola in gallons after h hours?

• f(h) = 75(-5)^h

• f(h) = -5(75)^h

• f(h) = .95(75)^h

• f(h) = 75(.95)^h

Write an exponential function to model the situation. You invest $1500. Your investment increases at a rate of 3.5%.

• B(t) = 1500(0.965)^t

• B(t) = 1500(1.035)^t

• B(t) = 1500(.035)^t

• B(t) = 1500(1.965)^t

Write an exponential function to model the situation. The value of a car is $18000 and is depreciating at a rate of 12% per year.

• V(t) = .88(18000)^t

• V(t) = .12(18000)^t

• V(t) = 18000(.88)^t

• V(t) = 18000(.12)^t