Closed sets. A subset S of a metric space M is closed, if its complement S...
In the following exercises, consider the metric space R with the discrete metric and the subset A [0, 1 C R. 15) True/False: A is closed. 16) True/False: A is open 17) True/False: Every point of A is a limit point of A. 18) Calculate the boundary of A. 19) True/False: For all Xo E X and all ε > 0, if B(x0, e) contains a point of A besides xo, then A C B(xo, e) In the following exercises,...
(a) Let (X, d) be a metric space. Prove that the complement of any finite set F C X is open. Note: The empty set is open. (b) Let X be a set containing infinitely many elements, and let d be a metric on X. Prove that X contains an open set U such that U and its complement UC = X\U are both infinite.
A point xo in a metric space X is said to be isolated if xo is not in the closure of X x0}. Using the Baire Category theorem, prove that the complement of any countable set is dense in X. Use this to show that an infinite complete metric space with no isolated points is uncountable.
Prove the Theorem: Let A and B be regularly closed sets in a metric space X. If aAnBº + then Aºn B° + Ø.
A. Let (X, d) be a metric space so that for every E X and every r>0 the closed ball N,(z) = {ye X : d(y, z) < r} is com pact. Let be a homeomorphism. (1) Prove that f"-+m-fn。fm for all n, m E Z. (2) Let z E X and suppose that F, {fn (z) : n E 2) is a closed subset of X Prove that F is a discrete subset of X (A subset Y C...
REAL ANALYSIS Question 1 (1.1) Let A be a subset of R which is bounded above. Show that Sup A E A. (1.2) Let S be a subset of a metric space X. Prove that a subset T of S is closed in S if and only if T = SA K for some K which is closed in K. (1.3) Let A and B be two subsets of a metric space X. Recall that A°, the interior of A,...
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...
topology class want proof for theorem 7.14 using definition 7.13 please explain well. Definition 7.13. X is a Baire space if the intersection of each countable family of dense open sets is dense. A set A c X is nowhere dense in X if (T)0-0, A set A C X is first category in X if A-Un=1 An, where each An is nowhere dense in X. If a set is not first category, it is called second category. (Topologically, seoond...
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...
Jet f be continuons one to one m compact metric space X onto a metric space Y. Prove that f'Y ~ X is continuoms (Hint: use this let X and Y e metric space, and let f be function from X to Y which is one to one and onto then the following three statments are equivalent. frs open, f is closed, f is continuous.