# Maths - Interval Notation

> Source: https://ollybritton.com/notes/a-level/maths/topics/interval-notation/ · Updated: 2021-08-09 · Tags: maths, school

## Flashcards
##### ![PHOTO OPEN INTERVAL](open-interval.png) What is this in interval notation??
$$
(a, b)
$$

##### ![PHOTO CLOSED INTERVAL](closed-interval.png) What is this in interval notation??
$$
[a, b]
$$

##### ![PHOTO HALF CLOSED LEFT](half-closed-left.png) What is this in interval notation??
$$
[a, b)
$$

##### ![PHOTO HALF CLOSED RIGHT](half-closed-right.png) What is this in interval notation??
$$
(a, b]
$$

##### $$(a, b)$$ What is this as an inequality for $x$??
$$
a < x < b
$$

##### $$[a, b]$$ What is this as an inequality for $x$??
$$
a \le x \le b
$$

##### $$[a, b)$$ What is this as an inequality for $x$??
$$
a \le x < b
$$

##### $$(a, b]$$ What is this as an inequality for $x$??
$$
a < x \le b
$$

###### What type of brackets are used for a closed interval??
Square, $[]$

###### What type of brackets are used for an open interval??
Circular, $()$

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