(Exercise 1.1.9) Let A, B C R be non-empty bounded sets such that B C A. Suppose that for all ï ¤ A, there exists a y € B such that x ≥ y. Show that inf B = inf A.

Advanced Engineering Mathematics
10th Edition
ISBN:9780470458365
Author:Erwin Kreyszig
Publisher:Erwin Kreyszig
Chapter2: Second-order Linear Odes
Section: Chapter Questions
Problem 1RQ
icon
Related questions
Question

Analysis

Review some useful properties of sup/inf.

**Exercise 1.1.9**  
Let \( A, B \subset \mathbb{R} \) be non-empty bounded sets such that \( B \subset A \). Suppose that for all \( x \in A \), there exists a \( y \in B \) such that \( x \geq y \). Show that \( \inf B = \inf A \).

**Hint:** You may find the following variant of Proposition 1.2.8 helpful: If \( S \subset \mathbb{R} \) is a nonempty bounded below set, then for every \( \varepsilon > 0 \) there exists \( x \in S \) such that \(\inf S \leq x < \inf S + \varepsilon\).
Transcribed Image Text:**Exercise 1.1.9** Let \( A, B \subset \mathbb{R} \) be non-empty bounded sets such that \( B \subset A \). Suppose that for all \( x \in A \), there exists a \( y \in B \) such that \( x \geq y \). Show that \( \inf B = \inf A \). **Hint:** You may find the following variant of Proposition 1.2.8 helpful: If \( S \subset \mathbb{R} \) is a nonempty bounded below set, then for every \( \varepsilon > 0 \) there exists \( x \in S \) such that \(\inf S \leq x < \inf S + \varepsilon\).
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps with 2 images

Blurred answer
Recommended textbooks for you
Advanced Engineering Mathematics
Advanced Engineering Mathematics
Advanced Math
ISBN:
9780470458365
Author:
Erwin Kreyszig
Publisher:
Wiley, John & Sons, Incorporated
Numerical Methods for Engineers
Numerical Methods for Engineers
Advanced Math
ISBN:
9780073397924
Author:
Steven C. Chapra Dr., Raymond P. Canale
Publisher:
McGraw-Hill Education
Introductory Mathematics for Engineering Applicat…
Introductory Mathematics for Engineering Applicat…
Advanced Math
ISBN:
9781118141809
Author:
Nathan Klingbeil
Publisher:
WILEY
Mathematics For Machine Technology
Mathematics For Machine Technology
Advanced Math
ISBN:
9781337798310
Author:
Peterson, John.
Publisher:
Cengage Learning,
Basic Technical Mathematics
Basic Technical Mathematics
Advanced Math
ISBN:
9780134437705
Author:
Washington
Publisher:
PEARSON
Topology
Topology
Advanced Math
ISBN:
9780134689517
Author:
Munkres, James R.
Publisher:
Pearson,