Set

If A= {1, 2, 3, 4} then A²=?

It’s a simple math. But matter of thinking. Just see it as multiplication. Become surprise? Don’t be... Look it like:

 A²=A*A.

 I hope now it become easier to you.

Solution:

Given that A= {1, 2, 3, 4}.

So,

 A2=A*A
= {1, 2, 3, 4}*{1, 2, 3, 4}
={(1,1),(1,2),(1,3),(1,4),(2,1),(2,2),(2,3),(2,4),(3,1),(3,2),(3,3),(3,4),(4,1),(4,2),(4,3),(4,4)}