Understanding Domain, Range, and Functions from Graphs

The video tutorial covers the concepts of domain, range, and functions using graphs. It explains how to determine the domain and range by reading from left to right and using brackets for closed intervals and parentheses for open intervals. The pencil test is introduced to check if a graph represents a function. Several examples are provided, including graphs with straight lines and circles, to illustrate these concepts. The video concludes with a summary of the key points discussed.

What are the x-values in a graph referred to as?

• Function

• Domain

• Interval

• Range

Which symbol is used for a closed interval?

• Parentheses

• Angle brackets

• Brackets

• Curly braces

In the first example, what is the domain of the graph?

• (-2, 2]

• [-2, 2]

• [-2, 2)

• (-∞, 2)

How do you determine if a graph represents a function?

• Check if x-values repeat

• Use the ruler test

• Use the pencil test

• Check if y-values repeat

What does an arrow on a graph indicate?

• A closed interval

• An open interval

• Infinite continuation

• A function

In the second example, what is the range of the graph?

• [-3, ∞)

• (-∞, 3]

• (-∞, 4]

• [-4, ∞)

For a straight line graph, how many values does the domain have?

• Infinite

• None

• Two

• One

In the third example, what is the range of the graph?

• (-∞, 3)

• (-∞, 3]

• (-3, ∞)

• (-3, ∞)

What shape of graph is used in the final example?

• Parabola

• Line

• Circle

• Ellipse

In the final example, why is the graph not a function?

• It is a closed shape

• It has repeating x-values

• It touches at two places

• It has repeating y-values