Chapter 7.1, Problem 4E

(a)

To determine

To prove: That $B$ is bounded above if $A$ is bounded above and $B\subseteq A$ .

(b)

To determine

To prove: That $B$is bounded below if $A$ is bounded below and $B\subseteq A$ .

(c)

To determine

To prove: That $A\cup B$ is bounded above if $A$ and $B$ are bounded above.

(d)

To determine

To prove: That $A\cup B$ is bounded below if $A$ and $B$ are bounded below.