Show that a metric space X is not connected if and only if there exists a continuous surjection f : X → {0, 1}.

Show that a metric space X is not connected if and only if there exists a...
i) Does Lebesgue lemma hold true in the plane? Justify your answer! ii) Let (X, d1) be a compact metric space and (Y, d2) a metric space. Suppose that f : X → Y is continuous. Use Lebesgue lemma to show that for every > 0 there exists δ > 0 such that if d1(x, y) < δ then d2(f(x), f(y)) < , that is, f is uniformly continuous.
A subset D of a metric space (X, d) is dense if every member of
X is a limit of a sequence of elements from D.
Suppose (X,d) and (Y,ρ) are metric spaces and D is a dense
subset of X.
1. Prove that if f : D -» Y is uniformly continuous then there exists an extension15 of f to a if dn (E D) e X define 7(x) lim f(d,) uniformly continuous function f:X * Y. Hint: 2....
(TOPOLOGY) Prove the following using the defintion:
Exercise 56. Let (M, d) be a metric space and let k be a positive real number. We have shown that the function dk defined by dx(x, y) = kd(x,y) is a metric on M. Let Me denote M with metric d and let M denote M with metric dk. 1. Let f: Md+Mk be defined by f(x) = r. Show that f is continuous. 2. Let g: Mx + Md be defined...
In this problem we show that any metric space (X, d) is homeomorphic to a bounded metric space. (a) Define ρ : X X R by Show that ρ defines a metric on X. Conclude that (X,p) is a bounded metric space. (b) Show that f : (X, d) → (X, p) given by f(x) = x is a homeomorphism ism. (c) Is it true that if (X, d) is complete then (X, ρ) is complete?
In this problem we...
* Exercise 10. Let M be a (non-empty) compact metric space and f: M → M a continuous map such that for every ε > 0 there exists x E M such that d(f(x), z) < E. Show that there exists y M such that f()y Hint: consider the map g: MR defined by g(x)=d(f(x),z).] [8 marks]
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.
Problem 1. Let (X, d) be a metric space and t the metric topology on X. (a) Fix a E X. Prove that the map f :(X, T) + R defined by f(x) = d(a, x) is continuous. (b) If {x'n} and {yn} are Cauchy sequences, prove that {d(In, Yn)} is a Cauchy sequence in R.
3. (a) Let (X, dx), (Y, dy) be two metric spaces, C C X connected, and f : X+Y continuous. Show that f(C) CY is connected.
Let (X, d) be a discrete space and let (Y, d′) be any metric space. Prove that any function f : (X, d) → (Y, d′) is continuous. (Namely, any function from a discrete space to any metric space is continuous.)
Let X be metric space, and let g:X + R be uniformly continuous and h: R+R be continuous. (c) If h is uniformly continuous on R, then goh is uniformly continuous. (b) If g(x) = {g(x) : x € X} is a bounded set,(i.e. there exists M > 0 such that g(x) < M for all X E X.) then go h is uniformly continuous.