Exploring Functions and Function Notation

The video tutorial reviews functions, focusing on determining if relations are functions, analyzing domains and ranges, and applying the vertical line test. It uses examples like swine flu cases over time to illustrate these concepts. The tutorial also covers mapping functions and concludes with encouragement for students to study and prepare for their quiz.

What does the function s(t) = 9t - 4 represent in the context of the swine flu?

• The number of people affected by swine flu in thousands

• The number of days since the outbreak

• The rate of infection per day

• The total population of the area

If s(t) = 9t - 4, how many people are affected by swine flu after 4 days?

• 36,000

• 40,000

• 32,000

• 28,000

How many days will it take for 23,000 people to be affected by swine flu if s(t) = 9t - 4?

• 2 days

• 3 days

• 4 days

• 5 days

What is a key characteristic of a function?

• It has repeating x-values

• It has no repeating x-values

• It has repeating y-values

• It has no repeating y-values

Which of the following is the domain of the function with x-values: Jim, Greg, Jorge, and Tyrell?

• {Jim, Greg, Jorge, Tyrell}

• {1, 2, 3, 4}

• {65, 88, 91, 94}

• {32, 23, 36, 9}

Why is the relation with x-values: -2, 0, -1, -2 not a function?

• It has repeating x-values

• It has no domain

• It has no range

• It has repeating y-values

What does the vertical line test determine?

• If a relation is not a function

• If a graph is linear

• If a graph is quadratic

• If a relation is a function

What is the domain of a function that extends infinitely to the left and right?

• (-∞, 0)

• (-∞, 1)

• (-∞, ∞)

• (0, ∞)

Why does the graph of a function that fails the vertical line test not qualify as a function?

• It has repeating y-values

• It does not intersect the vertical line

• It has repeating x-values

• It intersects the vertical line more than once

Which of the following is an example of a function?

• A graph with repeating y-values

• A graph that fails the vertical line test

• A graph with no repeating x-values

• A graph with two lines coming from one x-value