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Given $A$, $B$ are bounded subsets of $\Bbb R$. Prove

  1. $A\cup B$ is bounded.
  2. $\sup(A \cup B) =\sup\{\sup A, \sup B\}$.

Can anyone help with this proof?

  • 1
    (1) is very, very easy, and (2) isn’t much harder; do you have any ideas at all about how to proceed?2012-10-20
  • 0
    I am very positive that I got 1. But I am not sure how to start with the (2) one.2012-10-20

2 Answers 2