Question

U=(0,1,2,3,4,5...) A=(1,2,3,4,..) C=(2,4,6,8...)
A' U C

Answer 1

A' means elements which are not in set A.


U mean Union, means all the elements.

Answer 2

So, the interpration will be,all those elements which arent in A but in C.

Answer 3

i know we just did polpak.
is it the same way?

Answer 4

Ok, so A is all the natural (counting) numbers except 0.

Answer 5

C is all the even positive integers

Answer 6

so the union will be?

Answer 7

all the elements thats are in A and are in C

Answer 8

all the elements in A or in C.

Answer 9

Bah

Answer 10

All the elements in A' or in C

Answer 11

but what elements are in A' ?

Answer 12

Do you understand the significance of the U set you have there (not the union operator)

Answer 13

so it would be
A={1,2,3,4,5,6,7}

Answer 14

The ... means that the pattern continues forever.

Answer 15

so how do we determine when to stop the pattern?

Answer 16

it doesn't ever stop

Answer 17

A is all of the counting numbers except 0. It's elements are 1,2,3,...,400,401,402,...90021,90022,90023,... forever

Answer 18

To understand how to find A' you need to understand what that U set up there is for

Answer 19

ok... and C goes on forever too..

Answer 20

right

Answer 21

You see the U set right? You know it is different than \(\cup\) the union operator

Answer 22

yes.

Answer 23

no i dont know the difference

Answer 24

Ok, the union operator does what we talked about before.

Answer 25

The \(U\) set defines your 'universe'

Answer 26

the same in each element...

Answer 27

it is the set of all of the numbers you are concerned with.

Answer 28

ok

Answer 29

so what is different about the U set than the A set?

Answer 30

U they are all numbers and A is all odd numbers

Answer 31

A isn't all odd.. there is a 2 and a 4 in there.

Answer 32

wait... the only thing differnt is the 0

Answer 33

there is a 0 in U and No 0 in A

Answer 34

right. So A' is all the elements in U that are not in A.

Answer 35

ok.. correct.

Answer 36

So that would be?

A' = ?

Answer 37

1,2,3,4,...

Answer 38

no, that's A

Answer 39

What is in U that is NOT in A

Answer 40

You said it earlier

Answer 41

A={0}

Answer 42

A= {1,2,3,4...}
A' = {0}

Answer 43

Don't forget the ' sign

Answer 44

ok

Answer 45

So then. What is \[A' \cup C\]

Answer 46

and do the same for C?
C={C=(2,4,6,8...}
C'={0,1,3,5}

Answer 47

you don't care about C'

Answer 48

It wants A' union C

Answer 49

so A' U C={0}

Answer 50

\[A' \cup C\] is all the items in A' or in C

Answer 51

would it be the A' or the A answer? A'={0} and A= {1,2,3,4...}

Answer 52

Neither. It will be all the items in \(A'\) or in \(C\)

Answer 53

there is none of elements that are in either A' or C

Answer 54

I think you don't understand 'or'

Answer 55

Is 0 in A' or C?

Answer 56

no i dont.. :( i'm sorry to be a pain in the retrice.

Answer 57

No, it's fine. We'll fix it.

Answer 58

Is 0 in A' or C?

Answer 59

it is in A'

Answer 60

That's not a yes or no.

Answer 61

yes it is in A'

Answer 62

I'm not asking which one it's in. I'm asking is it in A' or C?

Answer 63

yes

Answer 64

Then it is in the union of the two.

Answer 65

Is 1 in A' or C?

Answer 66

yes

Answer 67

it is?

Answer 68

Which one?

Answer 69

no its not in either one

Answer 70

Right. So it's not in the union. Is 2 in A' or C?

Answer 71

yes
in C

Answer 72

doesn't matter which. If the answer is yes, then it's also in the union of the two.

Answer 73

So now, you should be able to tell me, what will all the items in the union of \(A'\) and \(C\) be?

Answer 74

ok. I think I'll pass ;)

Answer 75

C' U C={0,2,4,5,6,8,...}

Answer 76

lol

Answer 77

shoot..

Answer 78

A' \(\cup\)C you mean.

Answer 79

I know what you meant. Yeah that's right.

Answer 80

A' U C={0,2,4,5,6,8,...}

Answer 81

oh wait. You have a stray 5 in there.

Answer 82

sneaky 5's always popping in where they are not invited.

Answer 83

lol my fingers were getting typing happy.. lol

Answer 84

anyway, that's right (without the 5)

Answer 85

Remember!
If the element is in one OR the other, it is in the union.
If the element is in BOTH, it is in the intersection.

Answer 86

ok thank you