Proving Set Theory Union in Cartesian Products

rallycar18
Messages
9
Reaction score
0

Homework Statement



Suppose A,B,C are sets. Prove that

A× (B U C)= (AxB) U (C x A)
 
Last edited:
Physics news on Phys.org
Have you tried the usual inclusion both ways method?
 
VeeEight said:
Have you tried the usual inclusion both ways method?

I'm not familiar..
 
Well if A is contained in B and B is contained in A, then A=B.
 
assume x \in A \times (B \cup C). Think about the definitions of Cartesian product and union: what can you conclude about the element x; can you use this information to show x \in (A \times B) \cup (A \times C)?
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
Back
Top