Pearson Algebra 1 Common Core, 2015
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Pearson Algebra 1 Common Core, 2015 View details
5. Working With Sets
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Exercise 1 Page 197

How does roster form differ from set-builder notation?

Roster Form:
G={ 1, 3, 5, 7, 9, 11, 13, 15, 17 }
Set-Builder Notation:
G={x|x is an odd natural number less than 18}

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

We are given a few key pieces of information about this set of numbers: the numbers must be natural, odd, and less than18. Natural numbers are all whole numbers greater than 0, so the first number in the set is 1. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12...

The set only consists of odd numbers, so we can eliminate any even numbers from the set of all natural numbers. 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21... Finally, we know that the set only contains odd natural numbers that are less than18. We can now form the roster form of set G. G={ 1, 3, 5, 7, 9, 11, 13, 15, 17 }

Set-Builder Form

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 G. G = { x|x is an odd natural number less than18 }