Unit 3.2 Introduction to Inequalities and Notation
Linear Inequalities
Linear inequalities are a set of numbers that will meet a certain criteria on the number line
Example: A < x < B
Where x is a number or group of numbers or “sets” that fall between A and B
The notation{x│ } is read “the set of all x such that….” And is called set-builder notation. The vertical bar(│) is read “such that”. A statement following the bar gives a condition or restriction for the variable x
When using interval notation, it is important to note that a parenthesis ( ) indicates non inclusivity and a bracket [ ] indicates inclusivity
So A < x ≤ B could be written
(A , B]
Inequality Symbols
Union and Intersection Notation
Connecting compound inequalities with “and” and “or”
“And” indicates Intersection (∩)
Looking at all numbers that make both statements true
“Or” indicates Union (U)
Looking at numbers that make either inequality true