261 13 | Integral Domains Exercises It looked absolutely impossible. But it so happens that you go on worryin8 at a problem in science and it seems to get tired, and lies down and away lets you catch it. WILLIAM LAWRENCE BRAGGT 1. Verify that Examples 1 through 8 are as claimed. 2. Which of Examples 1 through 5 are fields? 3. Show that a commutative ring with the cancellation property (under multiplication) has no zero-divisors. 4. List all zero-divisors in Z2o: Can you see a relationship between the zero-divisors of Z and the units of Z20? 20 5. Show that every nonzero element of Z is a unit or a zero-divisor. 6. Find a nonzero element in a ring that is neither a zero-divisor nor a unit. п 7. Let R be a finite commutative ring with unity. Prove that every nonzero element of R is either a zero-divisor or a unit. What hap- pens if we drop the "finite" condition on R? 8. Let a 0 belong to a commutative ring. Prove that a is a zero- divisor if and only if a2b 0 for some b 0. 9. Find elements a, b, and c in the ring Z ZeZ such that ab, ac, and bc are zero-divisors but abc is not a zero-divisor. 10. Describe all zero-divisors and units of ZOQZ 11. Let d be an integer. Prove that Z[Vd] = {a + bVd a, b E Z} is an integral domain. (This exercise is referred to in Chapter 18.) 12. In Z,, give a reasonable interpretation for the expressions 1/2, -2/3, V-3, and - 1/6. 13. Give an example of a commutative ring without zero-divisors that is not an integral domain. 14. Find two elements a and b in a ring such that both a and b are zero- C pa divisors, a + b 0, and a + b is not a zero-divisor. 15. Let a belong to a ring R with unity and suppose that a" = 0 for some positive integer n. (Such an element is called nilpotent.) Prove that 1 a has a multiplicative inverse in R. [Hint: Consider (1- a)(1 + a + a2+ + a-1).] Bragg, at age 24, won the Nobel Prize for the invention of x-ray crystallography. He remains the youngest person ever to receive the Nobel Prize.

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
Topic Video
Question

4

261
13 | Integral Domains
Exercises
It looked absolutely impossible. But it so happens that you go on worryin8
at a problem in science and it seems to get tired, and lies down and
away
lets you catch it.
WILLIAM LAWRENCE BRAGGT
1. Verify that Examples 1 through 8 are as claimed.
2. Which of Examples 1 through 5 are fields?
3. Show that a commutative ring with the cancellation property
(under multiplication) has no zero-divisors.
4. List all zero-divisors in Z2o: Can you see a relationship between the
zero-divisors of Z and the units of Z20?
20
5. Show that every nonzero element of Z is a unit or a zero-divisor.
6. Find a nonzero element in a ring that is neither a zero-divisor nor a
unit.
п
7. Let R be a finite commutative ring with unity. Prove that every
nonzero element of R is either a zero-divisor or a unit. What hap-
pens if we drop the "finite" condition on R?
8. Let a 0 belong to a commutative ring. Prove that a is a zero-
divisor if and only if a2b 0 for some b 0.
9. Find elements a, b, and c in the ring Z ZeZ such that ab, ac,
and bc are zero-divisors but abc is not a zero-divisor.
10. Describe all zero-divisors and units of ZOQZ
11. Let d be an integer. Prove that Z[Vd] = {a + bVd a, b E Z} is
an integral domain. (This exercise is referred to in Chapter 18.)
12. In Z,, give a reasonable interpretation for the expressions 1/2,
-2/3, V-3, and - 1/6.
13. Give an example of a commutative ring without zero-divisors that
is not an integral domain.
14. Find two elements a and b in a ring such that both a and b are zero-
C
pa
divisors, a + b 0, and a + b is not a zero-divisor.
15. Let a belong to a ring R with unity and suppose that a" = 0 for
some positive integer n. (Such an element is called nilpotent.)
Prove that 1 a has a multiplicative inverse in R. [Hint: Consider
(1- a)(1 + a + a2+ + a-1).]
Bragg, at age 24, won the Nobel Prize for the invention of x-ray crystallography. He
remains the youngest person ever to receive the Nobel Prize.
Transcribed Image Text:261 13 | Integral Domains Exercises It looked absolutely impossible. But it so happens that you go on worryin8 at a problem in science and it seems to get tired, and lies down and away lets you catch it. WILLIAM LAWRENCE BRAGGT 1. Verify that Examples 1 through 8 are as claimed. 2. Which of Examples 1 through 5 are fields? 3. Show that a commutative ring with the cancellation property (under multiplication) has no zero-divisors. 4. List all zero-divisors in Z2o: Can you see a relationship between the zero-divisors of Z and the units of Z20? 20 5. Show that every nonzero element of Z is a unit or a zero-divisor. 6. Find a nonzero element in a ring that is neither a zero-divisor nor a unit. п 7. Let R be a finite commutative ring with unity. Prove that every nonzero element of R is either a zero-divisor or a unit. What hap- pens if we drop the "finite" condition on R? 8. Let a 0 belong to a commutative ring. Prove that a is a zero- divisor if and only if a2b 0 for some b 0. 9. Find elements a, b, and c in the ring Z ZeZ such that ab, ac, and bc are zero-divisors but abc is not a zero-divisor. 10. Describe all zero-divisors and units of ZOQZ 11. Let d be an integer. Prove that Z[Vd] = {a + bVd a, b E Z} is an integral domain. (This exercise is referred to in Chapter 18.) 12. In Z,, give a reasonable interpretation for the expressions 1/2, -2/3, V-3, and - 1/6. 13. Give an example of a commutative ring without zero-divisors that is not an integral domain. 14. Find two elements a and b in a ring such that both a and b are zero- C pa divisors, a + b 0, and a + b is not a zero-divisor. 15. Let a belong to a ring R with unity and suppose that a" = 0 for some positive integer n. (Such an element is called nilpotent.) Prove that 1 a has a multiplicative inverse in R. [Hint: Consider (1- a)(1 + a + a2+ + a-1).] Bragg, at age 24, won the Nobel Prize for the invention of x-ray crystallography. He remains the youngest person ever to receive the Nobel Prize.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 5 steps with 2 images

Blurred answer
Knowledge Booster
Discrete Probability Distributions
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
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,