Problem 61. Use the definition to prove lim,-o n100 # 0. n+100
Advanced Engineering Mathematics
10th Edition
ISBN:9780470458365
Author:Erwin Kreyszig
Publisher:Erwin Kreyszig
Chapter2: Second-order Linear Odes
Section: Chapter Questions
Problem 1RQ
Related questions
Question
100%
#61

Transcribed Image Text:**Convergence of Sequences and Series**
We can negate this definition to prove that a particular sequence does not converge to zero.
**Example 5.** Use the definition to prove that the sequence \((1 + (-1)^n)_{n=0}^\infty = (2, 0, 2, 0, 2, \ldots)\) does not converge to zero.
Before we provide this proof, let’s analyze what it means for a sequence \((s_n)\) to not converge to zero. Converging to zero means that any time a distance \(\varepsilon > 0\) is given, we must be able to respond with a number \(N\) such that \(|s_n| < \varepsilon\) for every \(n > N\). To have this not happen, we must be able to find some \(\varepsilon > 0\) such that no choice of \(N\) will work. Of course, if we find such an \(\varepsilon\), then any smaller one will fail to have such an \(N\), but we only need one to mess us up. If you stare at the example long enough, you see that any \(\varepsilon\) with \(0 < \varepsilon \leq 2\) will cause problems. For our purposes, we will let \(\varepsilon = 2\).
**Proof:** Let \(\varepsilon = 2\) and let \(N \in \mathbb{N}\) be any integer. If we let \(k\) be any non-negative integer with \(k > \frac{N}{2}\), then \(n = 2k > N\), but \(|1 + (-1)^n| = 2\). Thus no choice of \(N\) will satisfy the conditions of the definition for this \(\varepsilon\) (namely that \(|1 + (-1)^n| < 2\) for all \(n > N\)) and so \(\lim_{n \to \infty} (1 + (-1)^n) \neq 0\).
**Problem 60.** Negate the definition of \(\lim_{n \to \infty} s_n = 0\) to provide a formal definition for \(\lim_{n \to \infty} s_n \neq
Expert Solution

Step 1
Limits:
Let's pretend we have a function . The value that a function achieves when the variable x approaches a specific value, say a, is referred to as its limit. 'a' denotes a value that has already been allocated. It's referred to as
Step by step
Solved in 2 steps

Recommended textbooks for you

Advanced Engineering Mathematics
Advanced Math
ISBN:
9780470458365
Author:
Erwin Kreyszig
Publisher:
Wiley, John & Sons, Incorporated

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…
Advanced Math
ISBN:
9781118141809
Author:
Nathan Klingbeil
Publisher:
WILEY

Advanced Engineering Mathematics
Advanced Math
ISBN:
9780470458365
Author:
Erwin Kreyszig
Publisher:
Wiley, John & Sons, Incorporated

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…
Advanced Math
ISBN:
9781118141809
Author:
Nathan Klingbeil
Publisher:
WILEY

Mathematics For Machine Technology
Advanced Math
ISBN:
9781337798310
Author:
Peterson, John.
Publisher:
Cengage Learning,

