Sets

Question 1

What is a “set”?

Answer 1

A collection of elements (i.e. elements can be any type of number)

Question 2

What’s the difference between a finite set and an infinite set?

Answer 2

Finite: specific # of elements (A=3,4,5,6,7,8 There are six elements in this set)

Infinite: unlimited # of elements (W=0,1,2,3,4… the “…” denotes that the elements in the set continue on indefinitely. W represents all the Whole numbers)

Question 3

What is an empty set referred to as?

Answer 3

A “null” set

It does NOT have any elements in it and is represented as { } or a circle with a line slashed through it

Question 4

Can {0} be used to represent a null set?

Answer 4

No, because 0 is an element itself.

Question 5

What is a union of two sets?

Answer 5

When two separate sets are combined to create one larger set

Question 6

What is union of two sets denoted by?

Answer 6

‘U’

Question 7

What would the union of A and B look like?

A={1,2,3,4}

B={2,4,6,8}

Answer 7

A U B= {1,2,3,4,5,6,7,8}

You don’t write the numbers that A and B have in common twice

Question 8

What is the intersection of two sets?

Answer 8

An intersection of two sets mean that you only write the elements that are common to both sets. This is denoted by an upside down U

Question 9

Note to self: You are not done taking notes on ‘sets’.

Answer 9

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