: include_once(../../../../../site/defns.php): Failed to open stream: No such file or directory in
: include_once(): Failed opening '../../../../../site/defns.php' for inclusion (include_path='.:/usr/share/php') in
Let $(\mathcal M, d)$ be a metric space.
-
Suppose that $K_1, K_2 \subseteq M$ are compact.
Which is the weakest assumption below which guarantees that $K_1 \cup K_2$ is compact?
- $K_1\cap K_2 \neq \emptyset$.
- $M = \R^n$ for some $n \in \N$.
- $K_1 \subseteq K_2$.
- No further assumption.
-
Which of the following is the statement that the sequence $(a_n)_n$ does not converge?
- $\forall L \in M \, \forall r \gt 0 \, \exists N \, \forall n \gt N, \, d(a_n, L) \geq r$.
- $\exists L \in M \, \exists r \gt 0 \, \forall N \, \exists n \gt N, \, d(a_n, L) \geq r$.
- $\forall L \in M \, \exists r \gt 0 \, \forall N \, \exists n \gt N, \, d(a_n, L) \geq r$.
- $\exists L \in M \, \forall r \gt 0 \, \exists N \, \forall n \gt N, \, d(a_n, L) \geq r$.
-
If $E \subseteq M$ is not compact, then no infinite open cover of $E$ has a finite subcover.
- True.
- False.
-
If $(x_n)_n$ is a sequence which takes on only finitely many distinct values, it converges.
- True.
- False.