Math 0309
Integers
-3,-2,-1,0,1,2,3
whole numbers
0,1,2,3,4...
Natural numbers
1,2,3,...
rational number
A number that can be written as a fraction
⊆
A subset of or equal to. If every element of A is an element of B, then A is a subset of B.
real numbers
All numbers
U Union
Everything in group A and group B
logical connectives
Include and, or, not and if...then.
∀ Quantifiers
Indicate how many cases of a particular situation exists. All, Each, Every.
∈
It belongs to, member of, is an element of.
roster method
Listing each item in a set within braces
irrational numbers
Numbers that cannot be expressed as a ratio of two integers. Their decimal expansions are nonending and nonrepeating.
∃ Existential
Some, There exists, for at least one.
absolute value
The distance a number is from zero on a number line
∩ Intersection
The elements two or more sets have in common
statement
a sentence that is either true or false
` Prime
a whole number greater than 1 whose only factors are 1 and itself. A factor is a whole numbers that can be divided evenly into another number. The first few prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, 23 and 29.
Λ Conjunction
compound statement formed by joining two statements with the connector AND. The conjunction "p and q" is symbolized by p q. A conjunction is true when both of its combined parts are true; otherwise it is false.
∅
empty set; set with no elements
V disjunction
is false if and only if both statements are false; otherwise it is true.
x | x
such that
~ Negation
the opposite of the original statement