Let (n) and (yn) be Cauchy sequences. Using only the definition of Cauchy (and not using Theorem 2.6.4, or Algebraic Limit Theorems) prove that (xn+yn) is Cauchy.

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
100%
**Definition:** A sequence \((a_n)\) is called a *Cauchy sequence* if, for every \(\epsilon > 0\), there exists an \(N \in \mathbb{N}\) such that whenever \(m, n \geq N\) it follows that \(|a_n - a_m| < \epsilon\).
Transcribed Image Text:**Definition:** A sequence \((a_n)\) is called a *Cauchy sequence* if, for every \(\epsilon > 0\), there exists an \(N \in \mathbb{N}\) such that whenever \(m, n \geq N\) it follows that \(|a_n - a_m| < \epsilon\).
**Problem Statement:**

Let \((x_n)\) and \((y_n)\) be Cauchy sequences. Using only the definition of Cauchy (and not using Theorem 2.6.4, or Algebraic Limit Theorems) prove that \((x_n + y_n)\) is Cauchy.

---

**Explanation:**

This problem involves proving that the sum of two Cauchy sequences is itself a Cauchy sequence. Here, you are restricted to using only the fundamental definition of a Cauchy sequence. A Cauchy sequence is defined as a sequence where, for every positive real number \(\epsilon\), there exists a positive integer \(N\) such that for all integers \(m, n \geq N\), the difference \(|x_m - x_n|\) is less than \(\epsilon\). 

In this task, you are asked to apply this definition directly (without invoking certain theorems) to show that the sequence \((x_n + y_n)\) satisfies the same property, and therefore is also Cauchy.
Transcribed Image Text:**Problem Statement:** Let \((x_n)\) and \((y_n)\) be Cauchy sequences. Using only the definition of Cauchy (and not using Theorem 2.6.4, or Algebraic Limit Theorems) prove that \((x_n + y_n)\) is Cauchy. --- **Explanation:** This problem involves proving that the sum of two Cauchy sequences is itself a Cauchy sequence. Here, you are restricted to using only the fundamental definition of a Cauchy sequence. A Cauchy sequence is defined as a sequence where, for every positive real number \(\epsilon\), there exists a positive integer \(N\) such that for all integers \(m, n \geq N\), the difference \(|x_m - x_n|\) is less than \(\epsilon\). In this task, you are asked to apply this definition directly (without invoking certain theorems) to show that the sequence \((x_n + y_n)\) satisfies the same property, and therefore is also Cauchy.
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,