Exercise 2.51. Let A, C C X and B, D CY. (1) Show that Ax BC X x Y. (2) Prove or disprove: (X \ A) × (Y \B) = (X × Y)\ (A x B). (If disproved, what does hold?) (3) Show that (A x B)n (C × D) = (AnC) x (Bn D). (4) Can we replace n by U in the above statement? (If not, what does hold?) %3D

Algebra & Trigonometry with Analytic Geometry
13th Edition
ISBN:9781133382119
Author:Swokowski
Publisher:Swokowski
Chapter4: Polynomial And Rational Functions
Section4.6: Variation
Problem 9E
icon
Related questions
icon
Concept explainers
Topic Video
Question

Solve Exercise 2.51 and Exercise 2.53 in detail please.
Only attempt the question when you know the right answer.

Definition 2.50. Let X and Y be sets. The product of X and Y, denoted X x Y, is the
set of ordered pairs given by
X × Y := {(x, y) | x € X ^ y E Y}.
Exercise 2.51. Let A, C C X and B, D C Y.
(1) Show that A × B c X × Y.
(2) Prove or disprove: (X \ A) × (Y \ B) = (X × Y)\(A× B). (If disproved, what does
hold?)
(3) Show that (A × B) N (C × D) = (An C) × (BN D).
(4) Can we replace n by U in the above statement? (If not, what does hold?)
Definition 2.52. Let (X, Tx) and (Y, Ty) be spaces. The product topology on X × Y is the
topology generated by the basis
B := {U × V c X × Y | U € Tx ^ V E TY}.
Exercise 2.53. Show that the product topology is well-defined, that is, B in Definition 2.52
is a basis for a topology.
Problem 2.54. Give an example to show that the basis for the product topology on X x Y
is just a basis, and not generally a topology.
Theorem 2.55. Let X and Y be spaces, A с Х, В с Ү, аnd give X x Y the product
topology. The Ах В — Ах В.
Transcribed Image Text:Definition 2.50. Let X and Y be sets. The product of X and Y, denoted X x Y, is the set of ordered pairs given by X × Y := {(x, y) | x € X ^ y E Y}. Exercise 2.51. Let A, C C X and B, D C Y. (1) Show that A × B c X × Y. (2) Prove or disprove: (X \ A) × (Y \ B) = (X × Y)\(A× B). (If disproved, what does hold?) (3) Show that (A × B) N (C × D) = (An C) × (BN D). (4) Can we replace n by U in the above statement? (If not, what does hold?) Definition 2.52. Let (X, Tx) and (Y, Ty) be spaces. The product topology on X × Y is the topology generated by the basis B := {U × V c X × Y | U € Tx ^ V E TY}. Exercise 2.53. Show that the product topology is well-defined, that is, B in Definition 2.52 is a basis for a topology. Problem 2.54. Give an example to show that the basis for the product topology on X x Y is just a basis, and not generally a topology. Theorem 2.55. Let X and Y be spaces, A с Х, В с Ү, аnd give X x Y the product topology. The Ах В — Ах В.
Expert Solution
Step 1

Note: As per bartleby instruction when more then one question is given only one has to be answered. Please upload other separately.

(1) The aim is to show that A×BX×Y

Given that, A,CX, B,DY.

Now, it is known that,

A×B=a,b|aA, bB

It is given that,AX, BY.

So, A×BX×Y.

(2) The objective is to show that, X\A×Y\B=X×Y\A×B

This can be written as, 

X\A×Y\B=x,y|xX and xA, yY and yB=x,y|x,yX,Y and x,yA,B

Since xA,yB imply that, (x,y)A×B.

So, X\A×Y\B=X×Y\A×B.

steps

Step by step

Solved in 2 steps

Blurred answer
Knowledge Booster
Sample space, Events, and Basic Rules of Probability
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, advanced-math and related others by exploring similar questions and additional content below.
Recommended textbooks for you
Algebra & Trigonometry with Analytic Geometry
Algebra & Trigonometry with Analytic Geometry
Algebra
ISBN:
9781133382119
Author:
Swokowski
Publisher:
Cengage
Linear Algebra: A Modern Introduction
Linear Algebra: A Modern Introduction
Algebra
ISBN:
9781285463247
Author:
David Poole
Publisher:
Cengage Learning