Answer:
b. unbounded
e. x ≤ 9
Step-by-step explanation:
Interval notation
( or ) : Use parentheses to indicate that the endpoint is excluded.
[ or ] : Use square brackets to indicate that the endpoint is included.
A bounded interval is an interval that includes both its endpoints.
For the interval (-∞, 9]:
- The endpoint -∞ is not included.
- The endpoint 9 is included.
Therefore, the given interval is unbounded.
Inequality notation
- < means "less than"
- > means "more than"
- ≤ means "less than or equal to"
- ≥ means "more than or equal to"
Therefore, the given interval is represented by the inequality x ≤ 9.
To sketch the graph on a number line:
- Place a closed circle at 9.
- Shade to the left of the closed circle.
To sketch the graph on a coordinate plane:
- Plot a solid line at x = 9.
- Shade to the left of the line.
