1. Let (Q, d) be the metric space consisting of the set Q of rational numbers...
Let (Q, d) be the metric space consisting of the set Q of rational numbers with the standard metric d(x, y) = |x-yl. Show that the Heine Borel theorem fails for (Q,d). In other words, show that (Q, d) has a subset SCQ that is closed and bounded, but not compact
Let (Q, d) be the metric space consisting of the set Q of rational numbers with the standard metric d(x, y) = |x-yl. Show that the Heine Borel theorem fails for (Q,d). In other words, show that (Q, d) has a subset SCQ that is closed and bounded, but not compact
1.5.7 Prove the following separately Theorem 1.5.10. Let (X,d) be a metric space. (a) IfY is a compact subset of X, and Z C Y, then Z is compact if and only if Z is closed (b) IfY. Y are a finite collection of compact subsets of X, then their union Y1 U...UYn is also compact. (c) Every finite subset of X (including the empty set) is compact.
Let (X, d) be an infinite discrete metric space. Prove that any infinite subset of X is closed and bounded but NOT compact
1. Find the boundary and the interior for the following sets. Find the set of all accumulation points and the closure for the following sets. Classify each set as open, closed, or neither closed nor open. Use Heine-Borel theorem to determine whether it is a compact subset of R. A is closed/ open / neither closed nor open A is compact /not compact intB B is closed / open / neither closed nor open B is compact / not compact...
1. Let (X, d) be a metric space, and U, V, W CX subsets of X. (a) (i) Define what it means for U to be open. (ii) Define what it means for V to be closed. (iii) Define what it means for W to be compact. (b) Prove that in a metric space a compact subset is closed.
Using only the definition of compact sets in a metric space, give examples of: (a) A nonempty bounded set in (R", dp), for n > 2 and 1 < pく00, which is not compact. (b) A bounded subset Y of R such that (Y, dy) contains nonempty closed and bounded subsets which are not compact (here dy is the metric inherited from the usual metric in R) Using only the definition of compact sets in a metric space, give examples...
Real Analysis II Please do it without using Heine-Borel's theorem and do it only if you're sure Problem: Let E be a closed bounded subset of En and r be any function mapping E to (0,∞). Then there exists finitely many points yi ∈ E, i = 1,...,N such that Here Br(yi)(yi) is the open ball (neighborhood) of radius r(yi) centered at yi. Also, following definitions & theorems should help that E CUBy Definition. A subset S of a topological...
It's given the following metric space [ir?,d) with the euclidean norm and the set M= {Ixoy)ER?: Osxs1, Osyste} show or disprove that a) M is a closed set b) M is a bounded set c) M is compact
1. (a) Let d be a metric on a non-empty set X. Prove that each of the following are metrics on X: a a + i. d(1)(, y) = kd(x, y), where k >0; [3] ii. dr,y) d(2) (1, y) = [10] 1+ d(,y) The proof of the triangle inequality for d(2) boils down to showing b + > 1fc 1+a 1+b 1+c for all a, b, c > 0 with a +b > c. Proceed as follows to prove...