# Math Help - questions on sets

1. ## questions on sets

thanks

1234567

2. For the first consider: $A = \left\{ {1,2,4,6} \right\}\;\& \,B = \left\{ {1,2,3,5} \right\}$.

For the second one, what $A^2$ mean?
I have never seen it defined in a 'set' context.

3. thanks got the help,

A^2 and B^2 means the following

let A={1,2} and B={3,4}

then A^2={{1,1},{1,2},{2,1},{2,2}}

B^2={{3,3},{3,4},{4,3},{4,4}}

4. Originally Posted by 1234567
A^2 and B^2 means the following
let A={1,2} and B={3,4} then A^2={{1,1},{1,2},{2,1},{2,2}}
B^2={{3,3},{3,4},{4,3},{4,4}}
It appears that you mean the cross product. But the notation is incorrect.
$A\times A=\{(1,1),(1,2),(2,1),(2,2)\}$.

5. You might also want to think about the situation in which $A\cap B= \phi$.

6. thanks for the help.