Prove that If a and b are real numbers, then one and only one of the relations a<b, a=b, b>a holds.
You have posted a number of problems.
But you have shown no effort on your part.
So, it seems that you have no idea what is going on. Is that correct?
If it is not correct, please post some effort on your part.
Now if you cannot do that the it is time to see your instructor!