Roster Form:
R=∅ Set-Builder Notation:
R={x|x is an even natural number less than 2 }
Practice makes perfect
A set of numbers shown in roster form lists all elements belonging to the set. In set-builder notation, however, all of the elements in a set can be described using a logical statement.
Roster Form
This form requires us to list all the natural numbers that are even and less than 2. The only natural number that is less than 2 is 1. Since 1 is not an even number R is an empty set.
R=∅
Set-Builder Notation
Often, it is more compact and easier to understand a set of numbers if they are listed in set-builder notation instead. We will use the variable x and a logical statement to describe the elements of set R.
R={x|x is an even natural number less than 2 }
Alternative Solution
Empty Set Notation
Since the set R is an empty set, the set-builder notation or roster form answer could also be represented by {}.
