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
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       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.
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       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
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       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
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       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 ∪
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       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
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       �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
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       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