3-5 Working With Sets

Roster form lists the elements of a set within braces, { }.

The set of 1 and 2 {1,2)

The set of multiples of 2 {2, 4, 6, 8, . . .}

Set-builder notation describes the properties an element must have to be included in a set.

{x | x is a multiple of 2} is read as "the set of all real numbers x, such that x is a multiple of 2."

The empty set, or null set, is the set that contains no elements.

The empty set is a subset of every set.

 $\phi$  or $\left\{\right\}$  

The universal set or universe is the largest set you are working with.

The complement of a set is the set of all elements in the universe that are not in the set. The complement of A is A'

page 200

10/21/20

A compound inequality consists of two distinct inequalities joined by the word and or the word or.

You can write a compound inequality involving and as a single inequality.

x > 4 and x < 9 can be written as 4 < x < 9.