" Show that the integers m = 3* . 568 and n = 3k. 638, where k > 0, satisfy simultaneously t(m) = t(n), σ(m) = σ (n), and %3D Þ(m) = p(n) %3D

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

3

**Problems 7.2**

1. Calculate \( \phi(1001) \), \( \phi(5040) \), and \( \phi(36,000) \).

2. Verify that the equality \( \phi(n) = (\phi(n+1) = \phi(n+2)) \) holds when \( n = 5186 \).

3. Show that the integers \( n = 3^k \cdot 568 \) and \( n = 3^k \cdot 638 \), where \( k \geq 0 \), satisfy simultaneously:
   \[
   \tau(m) = \tau(n), \quad \sigma(m) = \sigma(n), \quad \text{and} \quad \phi(m) = \phi(n)
   \]

4. Establish each of the assertions below:
   (a) If \( n \) is an odd integer, then \( \phi(2n) = \phi(n) \).
   
   (b) If \( n \) is an even integer, then \( \phi(2n) = 2\phi(n) \).
   
   (c) \( \phi(3n) = 3\phi(n) \) if and only if 3 | \( n \).
   
   (d) \( \phi(3n) = 2\phi(n) \) if and only if 3 \(\nmid n\).
   
   (e) \( \phi(n) = n/2 \) if and only if \( n = 2^k \) for some \( k \geq 1 \).
   
   *Hint:* Write \( n = 2^k N \), where \( N \) is odd, and use the condition \( \phi(n) = n/2 \) to show that \( N = 1 \).

5. Prove that the equation \( \phi(n) = \phi(n + 2) \) is satisfied by \( n = 2(2p - 1) \) whenever \( p \) and \( 2p - 1 \) are both odd primes.

6. Show that there are infinitely many integers \( n \) for which \( \phi(n) \) is a perfect square.
   
   *Hint:* Consider the integers \( n = 2^{2k+1} \
Transcribed Image Text:**Problems 7.2** 1. Calculate \( \phi(1001) \), \( \phi(5040) \), and \( \phi(36,000) \). 2. Verify that the equality \( \phi(n) = (\phi(n+1) = \phi(n+2)) \) holds when \( n = 5186 \). 3. Show that the integers \( n = 3^k \cdot 568 \) and \( n = 3^k \cdot 638 \), where \( k \geq 0 \), satisfy simultaneously: \[ \tau(m) = \tau(n), \quad \sigma(m) = \sigma(n), \quad \text{and} \quad \phi(m) = \phi(n) \] 4. Establish each of the assertions below: (a) If \( n \) is an odd integer, then \( \phi(2n) = \phi(n) \). (b) If \( n \) is an even integer, then \( \phi(2n) = 2\phi(n) \). (c) \( \phi(3n) = 3\phi(n) \) if and only if 3 | \( n \). (d) \( \phi(3n) = 2\phi(n) \) if and only if 3 \(\nmid n\). (e) \( \phi(n) = n/2 \) if and only if \( n = 2^k \) for some \( k \geq 1 \). *Hint:* Write \( n = 2^k N \), where \( N \) is odd, and use the condition \( \phi(n) = n/2 \) to show that \( N = 1 \). 5. Prove that the equation \( \phi(n) = \phi(n + 2) \) is satisfied by \( n = 2(2p - 1) \) whenever \( p \) and \( 2p - 1 \) are both odd primes. 6. Show that there are infinitely many integers \( n \) for which \( \phi(n) \) is a perfect square. *Hint:* Consider the integers \( n = 2^{2k+1} \
Expert 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,