The units of a cartesian product?

Click For Summary

Discussion Overview

The discussion revolves around identifying the units in the Cartesian product of Z12 and Z6, including the calculation of their inverses. Participants explore the concept through examples and proofs related to number theory.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested, Homework-related

Main Points Raised

  • One participant identifies the units of Z12 as 1, 11, 5, and 7, and the units of Z6 as 1 and 5, suggesting the Cartesian product of these sets.
  • Another participant confirms the correctness of the initial identification of units.
  • A participant questions whether the total number of units in the Cartesian product is eight, listing specific pairs as examples.
  • One participant proposes that instead of seeking examples, it would be beneficial to prove that the units of the product are precisely the pairs of units.
  • A later reply suggests that proving the assertion is a straightforward task, encouraging the use of definitions to clarify the concept.

Areas of Agreement / Disagreement

Participants generally agree on the identification of units in Z12 and Z6, but there is a debate on the approach to understanding the Cartesian product and whether to focus on examples or proofs.

Contextual Notes

Some assumptions about the definitions of units and the properties of the Cartesian product may not be fully articulated, and the discussion does not resolve whether the proposed pairs are indeed all the units.

chuy52506
Messages
77
Reaction score
0
Find all units in Z12 X Z6 and their inverses.

What i did was find the units of Z12 which are 1,11,5,7 then the ones of Z6 which are 1,5 and take the cartesian product of those two sets?
 
Physics news on Phys.org
Yes, that would be correct!
 
So there would be eight?
1,1 1,5 11,1 11,5 5,1 5,5 7,1 and 7,5?
 
Instead of asking this, why don't you try to prove that the units of the product are precisely the pairs of units?
 
Because it helps to do an example before. So is this correct?
 
micromass already answered that question. If you're still not entirely sure, my advice stands: prove it! (it's quite easy; it's a matter of writing out the definitions)
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 16 ·
Replies
16
Views
3K
  • · Replies 13 ·
Replies
13
Views
4K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 6 ·
Replies
6
Views
924
  • · Replies 14 ·
Replies
14
Views
3K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 33 ·
2
Replies
33
Views
5K