- #1
Max.Planck
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Homework Statement
Let [tex]B=\left\{{\frac{1}{2},\frac{2}{3},\frac{3}{4},...}\right\} [/tex]
Prove sup B = 1
Homework Equations
Archimedean principle:
Let a<b and a>0 [tex]\exists n \in{N}[/tex] such that an > b.
The Attempt at a Solution
Its trivial to see that 1 is an upper bound for B and B is nonempty, so B must have a finite supremum by the completeness axiom.
I want to show that 1 is the smallest upper bound. So I want to try to do a proof by contradiction:
Let M be an upper bound for B, and M<0.
-- Find contradiction ?
I know each element in B is a/b, with natural numbers a and b and a<b. But how to continue further??
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