


Suppose IN = {1,2,3,4... } Take the metric space (Ryd) show that A = { 1...
2. Suppose that is, d) is a metric space. Show that is, d') is a metric space where dcx, y) d'{x,y) - It dex,y) Thint: Show first that dix,z)= X [d(x,y) + dry, 2] for some x with osxsl.]
show that the product metric space X and Y are topologically
equivalent
2. Suppose that metric space (X, d) is topologically equivalent to (Y, dh) for i-, n. Show that the product metric spaces X = Π-x, and Y = Π, Y, are topologica equivalent.
2. Suppose that metric space (X, d) is topologically equivalent to (Y, dh) for i-, n. Show that the product metric spaces X = Π-x, and Y = Π, Y, are topologica equivalent.
Assume a space-time n the dimension and g the metric
in said space-time.
(a) Show that it is always possible to find an
orthonormal basis {e1, e2, ... en}, such that:
hint, use induction.
b) Show that the signature of the metric is
independent of the chosen orthonormal basis.
(1) Let (X,d) be a metric space and A, B CX be closed. Prove that A\B and B\A are separated
(1) Let (X,d) be a metric space and A, B CX be closed. Prove that A\B and B\A are separated
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...
Let (X,d) be a metric space, SCX, pEX. 1. p is said to be a limit point for S iff Ve 0, (N(p,8)\{p})nS#0 2. Closure of S is cl(S)=SUS Show that B(p,e) C X is closed
8) Prove that C([O, 1]) is a metric space with the metric .1 d(f, g) = / If(x)-g(x)| dx. 9) Let (X, di) and (Y, d2) be metric spaces. a) Prove that X × Y is a metric space with the metric b) Prove that X x Y is a metric space with the metric
1. 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 (8 points).
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,...
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.