(8) Let a E G of order k. If for integers m, n we have a prove that m = n mod k. (9) Let a, b E G. Prove that o(a) = o(a-¹) and o(ab) = o(ba). (10) 'Let G be a group of even order. Prove that G has an element of order 2. ·problems donc guide ?? = an then

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
TUTORIAL 1: BASIC FACTS ON GROUPS
Dr. A Sacidi
Group structures, University of Limpopo, 2022
In Questions 1-10 below, G is a finite group and e is the identity element.
By o(a), we mean the order of the element a € G. That is, the least positive
integer m with a" = e.
(1) Prove that if G = p is a prime, then G has no non-trivial subgroups
(that is, the only subgroups of G are (e) and G),
(2) If a € G, then a² = e if and only if a = a-¹.
(3) If a, b E G then prove that (b-¹ab)" = b-lab for every integer n.
(4) Prove that G is abelian if for all a € G, we have a² = e (Hint: Use
Problem 2).
(5) Show with an example that the union of two subgroups is not always
a subgroup.
(6) Let Z(G) = {r € Glax = xa}. Prove that Z(G) is an abelian sub-
group of G (this subgroup is called the center of G).
(7) Let a E G be of order m and let k be a positive integer. Prove that
m/k if and only if ak = e (Hint: Use the division algorithm).
E
(8) Let a € G of order k. If for integers m, n we have a = a" then
prove that m = n mod k.
(9) Let a, b E G. Prove that o(a) = o(a-¹) and o(ab) = o(ba).
(10) 'Let G be a group of even order. Prove that G has an element of
order 2.
problems
done
guide ??
1This one is hard.
20
21
22
24
1
29
30
33
on
Transcribed Image Text:TUTORIAL 1: BASIC FACTS ON GROUPS Dr. A Sacidi Group structures, University of Limpopo, 2022 In Questions 1-10 below, G is a finite group and e is the identity element. By o(a), we mean the order of the element a € G. That is, the least positive integer m with a" = e. (1) Prove that if G = p is a prime, then G has no non-trivial subgroups (that is, the only subgroups of G are (e) and G), (2) If a € G, then a² = e if and only if a = a-¹. (3) If a, b E G then prove that (b-¹ab)" = b-lab for every integer n. (4) Prove that G is abelian if for all a € G, we have a² = e (Hint: Use Problem 2). (5) Show with an example that the union of two subgroups is not always a subgroup. (6) Let Z(G) = {r € Glax = xa}. Prove that Z(G) is an abelian sub- group of G (this subgroup is called the center of G). (7) Let a E G be of order m and let k be a positive integer. Prove that m/k if and only if ak = e (Hint: Use the division algorithm). E (8) Let a € G of order k. If for integers m, n we have a = a" then prove that m = n mod k. (9) Let a, b E G. Prove that o(a) = o(a-¹) and o(ab) = o(ba). (10) 'Let G be a group of even order. Prove that G has an element of order 2. problems done guide ?? 1This one is hard. 20 21 22 24 1 29 30 33 on
Expert Solution
steps

Step by step

Solved in 3 steps with 3 images

Blurred answer
Similar questions
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,