Keystone Algebra: Functions and Data Questions and Answers

Question 1

Which of the following sets of ordered pairs represents a function?

Accepted Answer

{(-2, 2), (-1, 5), (0, 8), (1, 5), (2, 2)}

Answer

{(3, 4), (5, -1), (3, 7), (8, 0)}

Answer

{(1, 1), (2, 2), (1, -1), (2, -2)}

Answer

{(-4, 9), (-4, 3), (0, 0), (4, 3)}

Question 2

A plumber charges a flat fee of $50 for a service call, plus an additional $75 per hour of labor. This relationship is modeled by the function C(h) = 75h + 50, where C(h) is the total cost and h is the number of hours of labor. What do the slope and y-intercept represent in this context?

Accepted Answer

The slope is the hourly rate, and the y-intercept is the flat fee.

Answer

The slope is the flat fee, and the y-intercept is the hourly rate.

Answer

The slope is the number of hours, and the y-intercept is the total cost.

Answer

The slope is the total cost, and the y-intercept is the number of hours.

Question 3

The table below shows some values for a function, f(x). Which of the following statements best describes this function?

| x | f(x) |
|---|---|
| -2| 4   |
| -1| 1   |
| 0 | 0   |
| 1 | 1   |
| 2 | 4   |

Accepted Answer

It is a nonlinear function because the rate of change is not constant.

Answer

It is a linear function because the x-values increase at a constant rate.

Answer

It is not a function because the f(x) values of 1 and 4 are repeated.

Answer

It is a linear function because it passes the vertical line test.

Question 4

What is the domain of the function f(x) = √(x - 3)?

Accepted Answer

x ≥ 3

Answer

All real numbers

Answer

x > 3

Answer

x ≤ 3

Question 5

A researcher is tracking the population of a certain species of bird. The population started at 80 and has been decreasing by 6 birds each year. Which function, P(t), correctly models the bird population after t years?

Accepted Answer

P(t) = 80 - 6t

Answer

P(t) = 80t - 6

Answer

P(t) = 6t - 80

Answer

P(t) = 80 + 6t

Question 6

Which of the following graphs represents y as a function of x?

Accepted Answer

A horizontal line

Answer

A vertical line

Answer

A circle

Answer

A sideways parabola opening to the right