Understanding Interval Notation and Graphing

The video tutorial explains how to use interval notation to represent real numbers. It begins with graphing numbers less than or equal to 3, using a closed circle on 3 and an arrow pointing left. The interval notation is written as (-∞, 3] with a square bracket indicating inclusion of 3. The second example covers numbers greater than -6, using an open circle on -6 and an arrow pointing right. The interval notation is (-6, ∞) with parentheses indicating exclusion of -6. The tutorial emphasizes correct order and notation for infinity.

What is the task we are asked to perform with interval notation?

• Indicate all real numbers greater than 3

• Indicate all real numbers less than or equal to 3

• Indicate all real numbers equal to 3

• Indicate all real numbers less than 3

When graphing numbers less than or equal to 3, what symbol is used at 3?

• Arrow

• Closed circle

• Square bracket

• Open circle

In interval notation, how is the inclusion of 3 indicated?

• Using an open circle

• Using a square bracket

• Using a closed circle

• Using a rounded parenthesis

What is the correct interval notation for all real numbers less than or equal to 3?

• [3, ∞)

• [3, -∞)

• (-∞, 3]

• (-∞, 3)

When graphing numbers greater than -6, what symbol is used at -6?

• Closed circle

• Arrow

• Square bracket

• Open circle

In the graph of numbers greater than -6, which direction does the arrow point?

• Down

• Right

• Left

• Up

What is the interval notation for all real numbers greater than -6?

• (-∞, -6]

• (-∞, -6)

• [-6, ∞)

• (-6, ∞)

Why do we use a rounded parenthesis for infinity in interval notation?

• Infinity is always included

• Infinity is a finite number

• Infinity is a variable

• Infinity is never included

What does an open circle on a graph indicate about the number at that point?

• The number is the endpoint of the interval

• The number is the midpoint of the interval

• The number is not included in the interval

• The number is included in the interval