Chapter 2.1

Question 1

What is a set?

Answer 1

A collection of objects

Question 2

What are objects that belong to a set called?

Answer 2

Elements (members)

Question 3

Natural numbers

Answer 3

Weird N={1,2,3,4…}

Counting numbers

Question 4

Whole numbers

Answer 4

W={0,1,2,3,4…}

Natural numbers plus 0

Question 5

Integers

Answer 5

Weird Z={…-3,-2,-1,0,1,2,3}

Question 6

Rational Numbers

Answer 6

Weird Q={X/y|x€Z, y€Z, y not equal 0}

This is all fractions, terminating decimals, and repeating decimals.

All integers are rational numbers

Question 7

Irrational Numbers

Answer 7

I= the set of all non-terminating, non-repeating decimals

Ex: square root of 2, e, Pi, and -1.010010001….

Question 8

Real Numbers

Answer 8

Weird R= {x| X€Q or X€I}

Question 9

Classify:

-3

Answer 9

Z, Q, R

Question 10

Weird N

Answer 10

Natural numbers

Question 11

W

Answer 11

Whole numbers

Question 12

Weird Z

Answer 12

Integers

Question 13

Weird Q

Answer 13

Rational numbers

Question 14

I

Answer 14

Irrational numbers

Question 15

Weird R

Answer 15

Real numbers

Question 16

2/3

Answer 16

Q, R

Question 17

Square root 3

Answer 17

I, R

Question 18

0.1111111…..

Answer 18

Q, R

Question 19

2

Answer 19

N, W, Z, Q, R

Question 20

0.030033000333

Answer 20

Q, R

Question 21

Tips

Answer 21

N-W-Z-Q-R
If Q then not I
If I then not Q