Lesson 0.2 Sets of Numbers, Compound Inequalities, and Interval Notation Part B
Set builder notation: set is named by capital letter
example: A = {x|x=2,7,9,15} would read: “Set A is the collection of x-values such that x=2,7,9,15”
lists a name for a set of values (those values are equal to variable x)
Interval notation: describe sections on the number line
example: [2, 5)
hard brackets, [ ], mean the value is INCLUDED in the set
soft brackets, ( ), mean the value is EXCLUDED from the set
in the example, 2 is included and 5 is not
always use a soft bracket for infinity
U = union, you can place it between two notations to exclude values inside a set
example: (-2, 5]U(9, 18]
This set of values would exclude terms from 5 to 9; the set including 5 but not 9