# Set Theory Proof with Cartesian Product of Sets and Intersection A x (B n C) = (A x B) n (A x C) | Summary and Q&A

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December 20, 2018
by
The Math Sorcerer
Set Theory Proof with Cartesian Product of Sets and Intersection A x (B n C) = (A x B) n (A x C)

## TL;DR

The video explains a proof showing that the intersection of three sets (a cross b intersection c) is equal to a cross (b intersection c).

## Key Insights

• 😵 The video presents a proof that demonstrates the equality of the intersection and cross product operations.
• 😫 The proof relies on the understanding of ordered pairs and set operations.
• 🫵 By showing the step-by-step derivation of the proof, the presenter helps viewers understand the underlying logic.
• 😵 The proof highlights the relationship between set intersections and cross products.
• 😒 The use of clear notation and definitions aids in understanding the proof.
• ❓ The presenter emphasizes the importance of carefully defining the operations and components involved.
• 😫 The proof showcases the applicability of set theory in mathematical proofs.

## Transcript

hey what's up YouTube and this problem going to prove that a cross the intersection C is equal to a cross B intersection a cross C let's go ahead and go with the proof before we do it though let's recall what we mean by this by this X by this cross single so we're all if you have okay so if you have a cross B is in the set so we use these brackets ... Read More

## Questions & Answers

### Q: What is the definition of a cross product of two sets?

The cross product of two sets A and B is a set of all ordered pairs (x, y) where x belongs to A and y belongs to B.

### Q: How does the proof demonstrate the equality of the intersection and cross product operations?

The proof starts with the intersection of three sets and shows that the ordered pairs in this intersection can also be represented as the cross product of two sets, which includes the intersected set.

### Q: Can you explain the significance of the intersection in the proof?

The intersection allows us to consider only the ordered pairs where the second component (y) belongs to both sets, creating a tighter relationship between the sets.

### Q: How does the proof justify the final statement that the ordered pair is in the intersection?

By showing that the ordered pair is both in a cross b and in a cross c, the proof establishes that it satisfies the criteria for inclusion in the intersection of these two cross products.

## Summary & Key Takeaways

• The video presents a proof that shows how the intersection of three sets is equal to the cross product of two of the sets intersected with the third set.

• The proof begins by defining the meaning of a cross product of two sets using ordered pairs.

• The presenter shows step-by-step how the proof is derived, explaining the logic behind each statement and how it relates to the intersection and cross product operations.