Intuitively the difference between to elements in S is the biggest when one is the biggest element while the other one is the smallest (or vice versa).
Respected, the idea i have is that difference between two numbers is greatest when one is largest and other is smallest in S. but i don't know how to write the proof in proper way.
Respected, the idea i have is that difference between two numbers is greatest when one is largest and other is smallest in S. but i don't know how to write the proof in proper way.
Use the characterization that if is bounded then if and only if is an upper bound of and for every there exists such that .