Upper and Lower bounds? Completely confused! Please help!

aruv | Student

The concept of the Upper bounds and lower bound in general used in theory of sets and function .

Let us explain it for you. Consider a set

`S={1/n:n inN }` or


The highest elememnt in the set S is 1.

and lowest element  0 which is not in S (because there does not exist a real number when it divide 1 get 0)

But you can understand from here `1/(n+1)>0 AA n`

Thus  0 is lower bound and 1 is an upper bound of set S.

i.e.   `0<x<=1 AA x in S`