(a) Prove that, for each k E N, b - Ck = ak and b+ Ck = |ak]. (b) Prove that, if ak converges conditionally, then b and C both diverge.
(a) Prove that, for each k E N, b - Ck = ak and b+ Ck = |ak]. (b) Prove that, if ak converges conditionally, then b and C both diverge.
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
Topic Video
Question
![### Problem Description
**Sequence Definitions:**
Let \(\{a_k\}\) be a sequence of real numbers and sequences \(\{b_k\}\) and \(\{c_k\}\) be defined by the following rules:
\[
b_k =
\begin{cases}
a_k & \text{if } a_k > 0 \\
0 & \text{if } a_k \leq 0
\end{cases}
\quad \text{and} \quad
c_k =
\begin{cases}
-a_k & \text{if } a_k < 0 \\
0 & \text{if } a_k \geq 0
\end{cases}
\]
**Statements to Prove:**
(a) Prove that, for each \( k \in \mathbb{N} \), \(b_k - c_k = a_k\) and \(b_k + c_k = |a_k|\).
(b) Prove that, if \(\sum a_k\) converges conditionally, then \(\sum b_k\) and \(\sum c_k\) both diverge.
### Explanation of Problem Components
**Sequences \(\{a_k\}\), \(\{b_k\}\), \(\{c_k\}\):**
- The sequence \(\{a_k\}\) is any sequence of real numbers.
- The sequence \(\{b_k\}\) includes only the positive values from \(\{a_k\}\) and sets everything else to 0.
- The sequence \(\{c_k\}\) includes the negative values from \(\{a_k\}\) as positive (since \(c_k = -a_k\)) and sets everything else to 0.
### Detailed Steps
**Part (a):**
1. **To show \(b_k - c_k = a_k\):**
- If \(a_k > 0\), then
- \(b_k = a_k\),
- \(c_k = 0\),
- Thus, \(b_k - c_k = a_k - 0 = a_k\).
- If \(a_k \leq 0\), then
- \(b_k = 0\),
- \(c_k = -a_k\) (note: \(-a_k\) is](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F87a5eb21-df18-43d0-b53f-a372e6adca02%2F620e8e1d-ee94-427e-a3f3-6ecdbb39e30b%2Fmcm96oe_processed.jpeg&w=3840&q=75)
Transcribed Image Text:### Problem Description
**Sequence Definitions:**
Let \(\{a_k\}\) be a sequence of real numbers and sequences \(\{b_k\}\) and \(\{c_k\}\) be defined by the following rules:
\[
b_k =
\begin{cases}
a_k & \text{if } a_k > 0 \\
0 & \text{if } a_k \leq 0
\end{cases}
\quad \text{and} \quad
c_k =
\begin{cases}
-a_k & \text{if } a_k < 0 \\
0 & \text{if } a_k \geq 0
\end{cases}
\]
**Statements to Prove:**
(a) Prove that, for each \( k \in \mathbb{N} \), \(b_k - c_k = a_k\) and \(b_k + c_k = |a_k|\).
(b) Prove that, if \(\sum a_k\) converges conditionally, then \(\sum b_k\) and \(\sum c_k\) both diverge.
### Explanation of Problem Components
**Sequences \(\{a_k\}\), \(\{b_k\}\), \(\{c_k\}\):**
- The sequence \(\{a_k\}\) is any sequence of real numbers.
- The sequence \(\{b_k\}\) includes only the positive values from \(\{a_k\}\) and sets everything else to 0.
- The sequence \(\{c_k\}\) includes the negative values from \(\{a_k\}\) as positive (since \(c_k = -a_k\)) and sets everything else to 0.
### Detailed Steps
**Part (a):**
1. **To show \(b_k - c_k = a_k\):**
- If \(a_k > 0\), then
- \(b_k = a_k\),
- \(c_k = 0\),
- Thus, \(b_k - c_k = a_k - 0 = a_k\).
- If \(a_k \leq 0\), then
- \(b_k = 0\),
- \(c_k = -a_k\) (note: \(-a_k\) is
Expert Solution
![](/static/compass_v2/shared-icons/check-mark.png)
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
Step by step
Solved in 4 steps with 4 images
![Blurred answer](/static/compass_v2/solution-images/blurred-answer.jpg)
Knowledge Booster
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
![Advanced Engineering Mathematics](https://www.bartleby.com/isbn_cover_images/9780470458365/9780470458365_smallCoverImage.gif)
Advanced Engineering Mathematics
Advanced Math
ISBN:
9780470458365
Author:
Erwin Kreyszig
Publisher:
Wiley, John & Sons, Incorporated
![Numerical Methods for Engineers](https://www.bartleby.com/isbn_cover_images/9780073397924/9780073397924_smallCoverImage.gif)
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…](https://www.bartleby.com/isbn_cover_images/9781118141809/9781118141809_smallCoverImage.gif)
Introductory Mathematics for Engineering Applicat…
Advanced Math
ISBN:
9781118141809
Author:
Nathan Klingbeil
Publisher:
WILEY
![Advanced Engineering Mathematics](https://www.bartleby.com/isbn_cover_images/9780470458365/9780470458365_smallCoverImage.gif)
Advanced Engineering Mathematics
Advanced Math
ISBN:
9780470458365
Author:
Erwin Kreyszig
Publisher:
Wiley, John & Sons, Incorporated
![Numerical Methods for Engineers](https://www.bartleby.com/isbn_cover_images/9780073397924/9780073397924_smallCoverImage.gif)
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…](https://www.bartleby.com/isbn_cover_images/9781118141809/9781118141809_smallCoverImage.gif)
Introductory Mathematics for Engineering Applicat…
Advanced Math
ISBN:
9781118141809
Author:
Nathan Klingbeil
Publisher:
WILEY
![Mathematics For Machine Technology](https://www.bartleby.com/isbn_cover_images/9781337798310/9781337798310_smallCoverImage.jpg)
Mathematics For Machine Technology
Advanced Math
ISBN:
9781337798310
Author:
Peterson, John.
Publisher:
Cengage Learning,
![Basic Technical Mathematics](https://www.bartleby.com/isbn_cover_images/9780134437705/9780134437705_smallCoverImage.gif)
![Topology](https://www.bartleby.com/isbn_cover_images/9780134689517/9780134689517_smallCoverImage.gif)