If A = {0, 1, 2, 3} and B = {…−3, −2, −1}, what is A ∩ B?

Question

jim_thompson5910 · Answer

What do sets A and B have in common?

anonymous · Answer

they have the same numbers ? @jim_thompson5910

jim_thompson5910 · Answer

can you list any number that is in BOTH sets ?

anonymous · Answer

i knew to this so i dont really know how to do it...

jim_thompson5910 · Answer

the number 2 lies in which set

anonymous · Answer

A ?

jim_thompson5910 · Answer

but it's not in B, agreed?

anonymous · Answer

yes theres -2 in b

jim_thompson5910 · Answer

no, that's negative 2 (not positive 2)

anonymous · Answer

yeah thats what i said ..

jim_thompson5910 · Answer

You can do this with any number. You will find it in one set, but not the other.

jim_thompson5910 · Answer

Another example: the number -4 is in set B, but it's not in set A.

anonymous · Answer

ok @jim_thompson5910

jim_thompson5910 · Answer

so what can you tell me about the intersection of the two sets?

anonymous · Answer

i dont really know im knew to this..

jim_thompson5910 · Answer

Let's do a simpler example

The sets A = {1, 2} and B = {5, 10} have nothing in common. In other words, each number in each set only belongs to one set only.

So $\Large A \cap B = \emptyset$ which means that the intersection of sets A and B is the empty set

jim_thompson5910 · Answer

The empty set is a way of saying "nothing" but in a mathematical way.