Question

Exercise 4.11. For each of the following, state whether it is true or false. If true,...

Exercise 4.11. For each of the following, state whether it is true or false. If true, prove. If false, provide a counterexample.

  1. (i) LetX andY besetsfromRn. IfX⊂Y thenX is closed if and only if Y is closed.

  2. (ii) Let X and Y be sets from Rn. If X ∩Y is closed and convex then eitherX or Y is closed and convex (one or the other).

  3. (iii) LetX beanopensetandY ⊆X. IfY ≠∅,thenY isaconvexset.

  4. (iv) SupposeX isanopensetandY isaconvexset. IfX∩Y ⊂X then

    X∪Y is open.

  5. (v) If AandB are closed sets,and A∩B=∅ then A∪B is a closed set.

Homework Answers

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Exercise 4.11. For each of the following, state whether it is true or false. If true,...
Exercise 4.11. For each of the following, state whether it is true or false. If true, prove. If false, provide a counterexample. (i) Let X and Y be sets from Rn. If X ⊂ Y then X is closed if and only if Y is closed. (ii) Let X and Y be sets from Rn. If X ∩Y is closed and convex then either X or Y is closed and convex (one or the other). (iii) Let X be an...
1) For each of the following state whether it is true or false. If true give...
1) For each of the following state whether it is true or false. If true give one sentence exolanation. If false, give counterexample. a)If f is differentiable on (0,1) and f is increasing on (0,1) then f' > 0 on (0,1) b)Suppose that f is thrice differentiable function defined on (-1,1). Suppose that the second order Taylor polynomial of f at 0 is 1-x^2. Then f has a local extremum at 0.
4. For the following claims, state whether they are TRUE or FALSE. Statements claimed to be...
4. For the following claims, state whether they are TRUE or FALSE. Statements claimed to be TRUE must be accompanied by a proof, and statements claimed to be FALSE must be accompanied by a counterexample. (a) Let A and B be events in the sample space S. Then P(A ∩ B) ≤ P(A)P(B). (b) Let E be an event with 0 < P(E) < 1 and define PE(A) = P(A ∩ E) for every event A in the sample space...
True or false; for each of the statements below, state whether they are true or false....
True or false; for each of the statements below, state whether they are true or false. If false, give an explanation or example that illustrates why it's false. (a) The matrix A = [1 0] is not invertible.                               [1 -2] (b) Let B be a matrix. The rowspaces row (B), row (REF(B)) and row (RREF(B)) are all equivalent. (c) Let C be a 5 x 7 matrix with nullity 3. The rank of C is 2. (d) Let D...
1. In this problem, the domain of x is integers. For each of the statements, indicate...
1. In this problem, the domain of x is integers. For each of the statements, indicate whether it is TRUE or FALSE then write its negation and simplify it to the point that no ¬ symbol occurs in any of the statements (you may, however, use binary symbols such as ’̸=’ and <). i. ∀x(x+ 2 ≠ x+3) ii. ∃x(2x = 3x) iii. ∃x(x^2 = x) iv. ∀x(x^2 > 0) v. ∃x(x^2 > 0) 2. Let A = {7,11,15}, B...
(a) Let the statement, ∀x∈R,∃y∈R G(x,y), be true for predicate G(x,y). For each of the following...
(a) Let the statement, ∀x∈R,∃y∈R G(x,y), be true for predicate G(x,y). For each of the following statements, decide if the statement is certainly true, certainly false,or possibly true, and justify your solution. 1 (i) G(3,4) (ii) ∀x∈RG(x,3) (iii) ∃y G(3,y) (iv) ∀y¬G(3,y)(v)∃x G(x,4)
Is the following statement true? "If f (Y − X) = f (Y ) − f...
Is the following statement true? "If f (Y − X) = f (Y ) − f (X) for all sets X and Y with X ⊆ Y ⊆ A, then f : A → B is injective." Please provide a proof if it is true, and a counterexample if it is false.
Given that A, B, and C are sets, determine if each statement below is true or...
Given that A, B, and C are sets, determine if each statement below is true or false. Prove your answer using set builder notation and logical equivalences and/or giving a counterexample. i. If A ⋃ C = B ⋃ C, then A = B. ii. If A = B ⋃ C, then (A − C) ⋃ (B ∩ C) = B
State if true or false. If false, provide an explanation or counterexample. a) The series ∑n=1oo...
State if true or false. If false, provide an explanation or counterexample. a) The series ∑n=1oo (−1)? [(?4 2?)/3n] converges absolutely. b) The radius of convergence of the power series ∑ (0.25)? √(?)?? is 4.
For each of the following statements, identify whether the statement is true or false, and explain...
For each of the following statements, identify whether the statement is true or false, and explain why. Please limit each response to no more than 3 sentences. i) A p-value is the probability that the null hypothesis is false. ii) A chi-square test statistic can never be negative. iii) If we reject the null hypothesis that a population proportion is equal to a specific value, then that specific value will not be contained in the associated confidence interval. iv) If...