On Upper and lower bounds - Wikipedia, the free encyclopedia
it says "2 and 5 are both lower bounds for the set { 5, 10, 34, 13934}"
how is 2 a lower bound when it is not even in the set?
thanks in advance
On Upper and lower bounds - Wikipedia, the free encyclopedia
it says "2 and 5 are both lower bounds for the set { 5, 10, 34, 13934}"
how is 2 a lower bound when it is not even in the set?
thanks in advance
A lower bound for a set is defined as number with the property for all . It may be that in , but it doesn't have to be. If is a lower bound then it is automatically "the biggest lowerbound". Then is called a minimum of .
If we look at your example, where we look at the given set as a subset . Then are both lower bounds. They satisfy for all . Even better is a minimum of .