Question

A X B

Answer 1

@Hero can you help me ?

Answer 2

I'm assuming A and B are sets correct?

Answer 3

yes!

Answer 4

ok what sets are they

Answer 5

but what does it mean ?

Answer 6

i know what sets are

Answer 7

are you given what A and B are equal to?

Answer 8

Let A = {1, 2} and let B = {3, 4, 5}. Find A X B.

Answer 9

what does it mean though? does it mean like union?

Answer 10

A x B would be the set of all possible ordered pairs (a,b) where 'a' comes from set A and b comes from set B

Answer 11

kinda, but it's basically going through all the possible combinations of pairings

Answer 12

for example, (1,3) is in the set A x B

so is (2,5)

Answer 13

there are 6 elements total in set A x B

Answer 14

so...?

Answer 15

In general :
\[A\times B=\{(a,b)~~/ ~~a\in A,b\in B\}\]
i.e :
\[(a,b)\in A\times B\iff a\in A \text{ and } b\in B.\]

Answer 16

Hint: All of the set pairs have to be in the form (a,b):

So you'll have to pick one element from A, then pick one element from B and keep doing it until you've found all possible pairs.

Answer 17

so would it be 1,2,3,4,5?

Answer 18

As an example:

if A = {7,8} and B = {3, 4, 5, 6} then A x B = {(7,3),(7,4),(7,5),(7,6), (8,3),(8,4),(8,5), (8,6)}

Answer 19

so? {(1, 3), (1, 4), (1, 5), (2, 3), (2, 4), (2, 5)}

Answer 20

There ya go

Answer 21

YAY thankyou