Ch. 1.1 | Sets of Numbers

Question 1

Element

Answer 1

(or Member) Each object in the set.

Question 2

Ellipses

Answer 2

(…) The numbers continue on forever in the same pattern.

Question 3

Empty Set

Answer 3

(or Null Set) A set with no elements denoted { } or Ø

Question 4

Finite Set

Answer 4

The number of elements in a set is a whole number.

Question 5

Infinite Set

Answer 5

A set that is not finite; the set of natural numbers is an example of an infinite set since there is no largest natural number.

Question 6

Integer

Answer 6

The set of integers is written as
ℤ = {…,-3,-2,-1,0,1,2,3,…}

They can be represented on a number line. Positive numbers are to the right of zero, while negative numbers are to the left of zero.

Question 7

Intersection

Answer 7

( ∩ ) of sets is the set of elements common to all of the sets.

Question 8

Irrational number

Answer 8

ℚ’ (read “Q prime), consists of numbers that cannot be expressed as a ratio of integers.

Question 9

Member

Answer 9

(or Element) Each object in the set.

Question 10

Natural number

Answer 10

ℕ (or counting) numbers

ℕ = {1, 2, 3, …}

DOES NOT CONTAIN 0

Question 11

Null set

Answer 11

(or Empty Set) A set with no elements denoted { } or Ø

Question 12

Rational number

Answer 12

ℚ, consists of numbers that can be expressed as a ratio of two integers when the denominator is not equal to zero.

Question 13

Real number

Answer 13

ℝ, the union of the sets of rational numbers, ℚ, and irrational numbers, ℚ’,

Question 14

Set

Answer 14

A collection of objects.

Question 15

Subset

Answer 15

A set of another set if every element of the first is contained in the second.

Question 16

Union

Answer 16

( ∪ ) of sets is the set of elements that appear in any of the sets.

Question 17

Whole number

Answer 17

W = {0, 1, 2, 3, …}