Interval Notation

Front

What is interval notation?

Back

Interval notation is a mathematical notation used to represent a range of values on the number line. It uses parentheses and brackets to indicate whether endpoints are included or excluded.

Front

What does a closed interval [a, b] represent?

Back

A closed interval [a, b] includes both endpoints a and b, meaning that the values a and b are part of the interval.

Front

What does an open interval (a, b) represent?

Back

An open interval (a, b) excludes both endpoints a and b, meaning that the values a and b are not part of the interval.

Front

What does a half-open interval [a, b) represent?

Back

A half-open interval [a, b) includes the endpoint a but excludes the endpoint b, meaning that a is part of the interval while b is not.

Front

What does a half-open interval (a, b] represent?

Back

A half-open interval (a, b] excludes the endpoint a but includes the endpoint b, meaning that a is not part of the interval while b is.

Front

How is the interval notation for x > -9 expressed?

Back

The interval notation for x > -9 is written as (-9, ∞).

Front

How is the interval notation for x ≤ 5 expressed?

Back

The interval notation for x ≤ 5 is written as (-∞, 5].

Front

What symbols indicate a closed dot when graphing inequalities?

Back

The symbols ≤ and ≥ indicate a closed dot when graphing inequalities.

Front

What is the interval notation for -9 < x < -8.5?

Back

The interval notation for -9 < x < -8.5 is (-9, -8.5).

Front

What does the notation [∞, -5) represent?

Back

The notation [∞, -5) is incorrect; interval notation cannot have ∞ as a left endpoint.