Binary relation in a cartesian product

How many binary relation can be formed from the cartesian product below:
A = { 1 , 2 } & B = {a }
i know there are two ordered pairs in this cartesian products A * B.
i also know that there are 4 binary realtions. could someone please write
those four relations for me, i am really confused here.
 

HallsofIvy

Science Advisor
Homework Helper
41,644
839
{(1, a)}, {(2, a)}, {(a, 1)}, and {(a, 2)}.
 
{(1, a)}, {(2, a)}, {(a, 1)}, and {(a, 2)}.
I'd imagine, they're actually something more like these: {}, {(1, a)}, {(2, a)}, and {(1, a), (2, a)}...
 
thanx. i really apprecite u for this
 

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving
Top