Question

Find A union B.
A: {2, 4, 6, 8, 10, 12}
B: {−2, −1, 2, 4, 7, 11}

{2, 4}
{−2, −1, 2, 4, 6, 7, 8, 10, 11, 12}
{−2, −1, 1, 2, 4, 6, 8, 10}
{ }

Answer 1

The union of two sets is another set containing every member found in either of the two input sets.

Answer 2

So {2,4}??

Answer 3

No. I did not say "every member found in BOTH of the sets", I said "every member found in EITHER of the sets"

Answer 4

{2,4} is the intersection of the two sets — only the members which belong to both sets.

Answer 5

If I have two sets:

A = {pigs, cows}
B = {chickens, turkeys}

the union of the two sets would be {pigs, cows, chickens, turkeys}

Answer 6

Hmm what if i said {−2, −1, 2, 4, 6, 7, 8, 10, 11, 12} im stuck...

Answer 7

If you go down that list, do you find all of the members of set A?
If you go down that list, do you also find all of the members of set B?
If so, then that is the union of sets A & B

Answer 8

here's another example:

set A: {your mother's relatives}
set B: {your father's relatives}

the union of sets A&B is the set of your relatives

Answer 9

I dont see any soo just { }?

Answer 10

What?!?

Are you reading what I'm telling you?

You asked if {-2,-1,2,4,6,7,8,10,11,12} was a correct answer. I responded:
"If you go down that list, do you find all of the members of set A?
If you go down that list, do you also find all of the members of set B?
If so, then that is the union of sets A & B"

Let's look at set A: {2, 4, 6, 8, 10, 12}

Does 2 appear in {-2,-1,2,4,6,7,8,10,11,12}?
Does 4 appear in {-2,-1,2,4,6,7,8,10,11,12}
Does 6 appear in {-2,-1,2,4,6,7,8,10,11,12}
Does 8 appear in {-2,-1,2,4,6,7,8,10,11,12}
Does 10 appear in {-2,-1,2,4,6,7,8,10,11,12}
Does 12 appear in {-2,-1,2,4,6,7,8,10,11,12}

Answer 11

Yes it does

Answer 12

Okay, let's look at set B: {−2, −1, 2, 4, 7, 11}

Does -2 appear in {-2,-1,2,4,6,7,8,10,11,12}?
Does -1 appear in {-2,-1,2,4,6,7,8,10,11,12}?
Does 2 appear in {-2,-1,2,4,6,7,8,10,11,12}?
Does 4 appear in {-2,-1,2,4,6,7,8,10,11,12}?
Does 7 appear in {-2,-1,2,4,6,7,8,10,11,12}?
Does 11 appear in {-2,-1,2,4,6,7,8,10,11,12}?

Answer 13

yes

Answer 14

okay, so every member of set A and every member of set B appears in that set. That set is the union of sets A & B

Answer 15

It's easy to construct the set which is the union of two other sets. Just copy one of the sets, then go through the other set and add any elements which aren't in the one you just copied to the new list.

Answer 16

Thank you

Answer 17

So, if you were doing that procedure here, and copied set A:

union: {2, 4, 6, 8, 10, 12}
then looking at B: {-2,-1,2,4,7,11}

you would say "-2", not in union, add it
"-1", not in union, add it
"2" already in union
"4" already in union
"7" not in union, add it
"11" not in union, add it

and your union would be {2,4,6,8,10,12,-2,-1,7,11}
or {-2,-1,2,4,6,7,8,10,11,12} after you sorted it into order (which is not necessary, but makes it easier to read)

Answer 18

Okay got it