Jain College of Engineering, Belagavi
Department of Mathematics
Assignment – 4
Module 5: Group Theory
Course Name: Discrete Mathematical Structures Course Code: BCS405A
Semester : IV Maximum Marks : 20
Date: 17/05/2025 Date of Submission:
Q.NO Question CO PO RBT
If * is a an operation on Z defined by xy=x+y+1, prove that (Z,*) is an abelian
1 5 1 L2
group.
2 Define Group.Show that fourth roots of unity is an abelian group under 5 1 L2
3 Define Klein 4 Group .Verify A= 1,3,5,7 is a Klein 4 group. 5 1 L2
Show that i) the identity of G is unique.
4 5 1 L2
ii) the inverse of each element of G is Unique
Show that (A, .) is an abelian group where A= a ∈ Q/a ≠− 1 and for any
5 5 1 L2
a,b ϵA, a. b =a+b+ab.
If G be a set of all non-zero real numbers and let a*b =ab/2 then show that(G, *) is
6 5 1 L2
an abelian group
7 Prove that intersection of two subgroups of a group G is also a subgroup of G. 5 1 L2
8 Prove that (z4 , +) ia cyclic group.Find all its generators. 5 1
If H,K are subgroups of a group G, prove that H∩ K Is also a subgroup of G. Is H ∪
9 5 1 L2
K A subgroup of G ?
If G be a group with subgroup H and K .If G = 660 and K = 66 and K∁H∁G and
10 5 1 L2
�ind the possible value for H
11 Prove that intersection of two subgroups of a group G is also a subgroup of G 5 1 L2
12 State and prove Lagrange’s theorem. 5 1 L2
1 2 3 4
Let G=S4 for α = Find the subgroup H= < α > determine the left
13 2 3 4 1 5 1 L2
cosets of H in G.
Define cyclic group and show that (G,*) whose multiplication table is as given
below is cyclic
* a b c d e f
a a b c d e f
14 b b c d e f a 5 1 L2
c c d e f a b
d d e f a b c
e e f a b c d
f f a b c d e
*CO- Course Outcome: Demonstrate the application of discrete structures in different fields of
computer science.
Prepared By Scrutinized By Approved By
Signature: Signature: Signature:
Name:Dr.Manjula Kalyanshetti Name: Prof. Umesh S. Mujumdar Name: Dr. Prashant V Patil