Let (E,d) be a metric space and K, K' disjoint compact subsets
of E. Prove the...
Let (E,d) be a metric space and K, K' disjoint compact subsets
of E. Prove the existence of disjoint open sets U and U' containing
K and K' respectively.
Let A , B , and C be disjoint subsets of the sample space. For
each one of the following statements, determine whether it is true
or false. Note: "False" means "not guaranteed to be true."
a) P(A)+P(Ac)+P(B)=P(A∪Ac∪B)
b) P(A)+P(B)≤1
c) P(Ac)+P(B)≤1
d) P(A∪B∪C)≥P(A∪B)
e) P((A∩B)∪(C∩Ac))≤P(A∪B∪C)P((A∩B)∪(C∩Ac))≤P(A∪B∪C)
f) P(A∪B∪C)=P(A∩Cc)+P(C)+P(B∩Ac∩Cc)
)
Please explain how you got the answer.
(a) Let <X, d> be a metric space and E ⊆ X. Show
that E is connected iff for all p, q ∈ E, there is a connected A ⊆
E with p, q ∈ E.
b) Prove that every line segment between two points in R^k
is connected, that is Ep,q = {tp + (1 − t)q |
t ∈ [0, 1]} for any p not equal to q in R^k.
C). Prove that every convex subset of R^k...
Q2. Let (E, d) be a metric space, and let x ∈ E. We say that x
is isolated if the set {x} is open in E.
(a) Suppose that there exists r > 0 such that Br(x) contains
only finitely many points. Prove that x is isolated.
(b) Let E be any set, and define a metric d on E by setting d(x,
y) = 0 if x = y, and d(x, y) = 1 if x and y...
(Connected Spaces)
(a) Let <X, d> be a metric space and E ⊆ X. Show that E is
connected iff for all p, q ∈ E, there is a connected A ⊆ E with p,
q ∈ E.
b) Prove that every line segment between two points in R^k
is connected, that is Ep,q = {tp + (1 − t)q |
t ∈ [0, 1]} for any p not equal to q in R^k.
C). Prove that every convex subset...
Suppose K is a nonempty compact subset of a metric space X and x
∈ X.
(i) Give an example of an x ∈ X for which there exists distinct
points p, r ∈ K such that, for all q ∈ K, d(p, x) = d(r, x) ≤ d(q,
x).
(ii) Show, there is a point p ∈ K such that, for all other q ∈
K, d(p, x) ≤ d(q, x).
[Suggestion: As a start, let S = {d(x,...
Let (X,d) be a metric space. The graph of f : X → R is the set
{(x, y) E X X Rly = f(x)}. If X is connected and f is continuous,
prove that the graph of f is also connected.
Answer for a and be should be answered independently.
Let (X,d) be a metric space, and
a) let A ⊆ X. Let U be the set of isolated points of A. Prove
that U is relatively open in A.
b) let U and V be subsets of X. Prove that if U is both open and
closed, and V is both open and closed, then U ∩ V is also both open
and closed.