Cartesian Products: Set of Ordered Pairs?

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In summary, the cartesian product (A x B) is the set of all possible ordered pairs (a, b) where a is an element of A and b is an element of B. It is not just the set of all ordered pairs, as the order of the elements does matter in the cartesian product. Additionally, the cartesian product is not commutative and the Venn diagram of a cartesian product set would show the overlapping area of the two sets A and B.
  • #1
QuantumP7
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Is the cartesian product [tex] (A \times B) [/tex] the set of ALL POSSIBLE ordered pairs [tex] (a, b) [/tex] such that a is an element of A and b is an element of b, or is it simply the set of "all ordered pairs?"
 
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  • #2
Question for you: A = {1, 2, 3} and B = {cow, sheep}.Write down A x B.
 
  • #3
{1 cow, 2 cow, 3 cow; 1 sheep 2 sheep 3 sheep}?

So it's all possible ordered pairs?
 
  • #4
QuantumP7 said:
{1 cow, 2 cow, 3 cow; 1 sheep 2 sheep 3 sheep}?

correct

So it's all possible ordered pairs?

Your question is more a language thing about the word "possible".
 
  • #5
Yeah, I've gotten hung up on the semantics of all possible vs. all. But I think that I understand what's going on.

But does anyone know what the Venn diagram of a cartesian product set looks like?
 
  • #6
Outlined said:
correct
Not correct; AxB should consists of ordered pairs.
"1 cow" is not an ordered pair, "(1,cow)" is.
QuantumP7 said:
all possible vs. all.
What is or could be the difference?
 
  • #7
QuantumP7 said:
Is the cartesian product [tex] (A \times B) [/tex] the set of ALL POSSIBLE ordered pairs [tex] (a, b) [/tex] such that a is an element of A and b is an element of b, or is it simply the set of "all ordered pairs?"

If I understand you about trying to say that for example (1,cow) and (cow,1) are the same, then that is false. Cartesian products are not in general commutative since A x B takes the element of A and then B in the ordered pair. if A and B are the same set then you will have this property ( (a,b) and (b,a) are part of A x B) but generally this is not the case.
 
  • #8
Landau said:
Not correct; AxB should consists of ordered pairs.
"1 cow" is not an ordered pair, "(1,cow)" is.

You're right. My fault.

What is or could be the difference?

I get it now. All Cartesian products = all products. I think that I was just over-thinking the whole thing. Thanks so much!

chiro said:
If I understand you about trying to say that for example (1,cow) and (cow,1) are the same, then that is false. Cartesian products are not in general commutative since A x B takes the element of A and then B in the ordered pair. if A and B are the same set then you will have this property ( (a,b) and (b,a) are part of A x B) but generally this is not the case.

I see now. Thank you so much.
 

1. What is a Cartesian product?

A Cartesian product is a mathematical operation that combines two sets to create a new set of ordered pairs. The resulting set contains all possible combinations of elements from the two original sets.

2. How is a Cartesian product represented?

A Cartesian product is typically represented using the notation A x B, where A and B are the two sets being combined. For example, if A = {1, 2} and B = {a, b}, then A x B = {(1, a), (1, b), (2, a), (2, b)}.

3. What is the difference between a Cartesian product and a cross product?

A Cartesian product is a specific type of cross product, which is a more general mathematical operation that combines any number of sets to create a new set. A Cartesian product specifically combines two sets, while a cross product can combine more than two sets.

4. How is a Cartesian product useful in mathematics and science?

Cartesian products are useful in mathematics and science because they allow us to visualize and analyze relationships between different sets of data. They are also used in various mathematical operations, such as matrix multiplication and combinatorics.

5. Can a Cartesian product be empty?

Yes, a Cartesian product can be empty if one or both of the original sets are empty. For example, if A = {1, 2} and B = {}, then A x B = {} (an empty set). This is because there are no possible combinations of elements from A and B when B is empty.

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