# Interval Notation

``` Interval Notation- Uses inequalities to describe
subsets of real numbers.
 Example:
 This is an example of a Bounded Interval
 That is because x is in the middle or bound by the
numbers on the end
 We will use brackets and
parenthesis to represent the
numbers that x can be
 Since x can be equal to -2 we
use a bracket: [
 This means that x starts at -2
and can be equal to it
 Since x cannot be 6, we’ll use a
parenthesis )
 This means that x is less than
6 and cannot equal it
 Write an inequality to represent the following interval
notation:
Unbounded Interval
 Example: Write the following in interval notation:
 In this case the x is not in the middle of two numbers
 That means it’s not “bound”
 There are a infinite amount of numbers that are less
than 6, so we’re going to have to use the infinity sign
 Since x is smaller than 6, the 6 is the
right bound
 Use a bracket since it can be equal to
 The other side has an infinite number
of solutions, so we’ll use the infinity
sign
 Since it goes on forever in a negative
direction, ∞ has to be negative
 Since you can’t equal infinity, use a
parenthesis
```