If you have any questions do let me know in the comment section.
Please give a Thumbs up. Thanks in advance.
Stay Safe.
5. Let X be a topological space and let A and B be connected subsets of...
1- Prove or disprove. (X,Y are topological spaces, A, B are subsets of a topological space X, Ā denotes the closure of the set A, A' denotes the set of limit points of the set A, A° denotes the interior of the set A, A denotes the boundary of the set A.) (a) (AUB) = A'U Bº. (b) f-1(C') = (F-1(C))' for any continuous function f :X + Y and for all C CY. (c) If A° ), then A°=Ā.
4·Let A and B be non-empty subsets of a space X. Prove that A U B is disconnected if A n B)U(A nB) 0. Prove that X is connected if and only if for every pair of non-empty subsets A and B of X such that X A U B we have (A B)U (An B)O.
New problems for 2020 1. A topological space is called a T3.space if it is a T, space and for every pair («,F), where € X and F(carefull), there is a continuous function 9 :X (0,1 such that f(x) 0 and f =1 on F. Prove that such a space has the Hausdorff Separation Property. (Hint: One point subsets are closed.] 2. Let X be topological space, and assume that both V and W are subbases for the topology. Show...
l maps is a quotient map. 4, Let ( X,T ) be a topological space, let Y be a nonempty set, let f be a function that maps X onto Y, let U be the quotient topology on induced by f, and let (Z, V) be a topological space. Prove that a function g:Y Z is continuous if and only if go f XZ is continuous. l maps is a quotient map. 4, Let ( X,T ) be a topological...
5. Let A and B be compact subsets of R. (a) Prove that AnB is compact (b) Prove that AUB is compact. (c) Find an infinite family An of compact sets for which UAn is not compact. o-f (d) Suppose that An is a compact set for n 21. Prove that An is compact.
6. Prove that if a topological space X has the fixed point property, then X is connected
7. Let X = {a,b,c} and T = {x,ø,{a},{b}, {a,b}} be a topological space on X. Let f: X - X be such that f(a) = a, f(b)c and f(c) = b. Is f continuous at a? b? or c?
Please prove Theorem 7.20: Let (X, T) be a topological space. Then the following are all topological properties the number of elements in X, the number of T-open sets, and having a T-open set containing n elements (for any natural number n Theorem 7.20: Let (X, T) be a topological space. Then the following are all topological properties the number of elements in X, the number of T-open sets, and having a T-open set containing n elements (for any natural...
topology Note: Symbols have their usual meanings. 1. Show that every indiscrete topological space is locally connected. 2. Give an example of locally connected topological space which is not connected. 3. Show that the intersection of any collection of closed compact subsets of a topological space is closed and compact. (2)