# Supremum & infimum of the set of all rational numbers

1. Jun 30, 2011

### rohithsen

Hi everybody,
Please help me to find supremum & infimum of the set of rational numbers between √2 to √3

(ie) sup & inf of {x/ √2 < x < √3 , where x is rational number}

2. Jun 30, 2011

### micromass

Staff Emeritus
Hi rohitshen!

If you tell us what you've tried then we'll know where to help! Did you have any guess for what the sup and inf could be?

3. Jun 30, 2011

### mathman

There is an approach to defining real numbers (Dedekind cut) where √2 and √3 would be defined as the inf and sup respectively.