Date | May 2016 | Marks available | 3 | Reference code | 16M.3srg.hl.TZ0.1 |
Level | HL only | Paper | Paper 3 Sets, relations and groups | Time zone | TZ0 |
Command term | Copy and complete | Question number | 1 | Adapted from | N/A |
Question
The following Cayley table for the binary operation multiplication modulo 9, denoted by ∗, is defined on the set S={1, 2, 4, 5, 7, 8}.
Copy and complete the table.
Show that {S, ∗} is an Abelian group.
Determine the orders of all the elements of {S, ∗}.
(i) Find the two proper subgroups of {S, ∗}.
(ii) Find the coset of each of these subgroups with respect to the element 5.
Solve the equation 2∗x∗4∗x∗4=2.
Markscheme
A3
Note: Award A3 for correct table, A2 for one or two errors, A1 for three or four errors and A0 otherwise.
[3 marks]
the table contains only elements of S, showing closure R1
the identity is 1 A1
every element has an inverse since 1 appears in every row and column, or a complete list of elements and their correct inverses A1
multiplication of numbers is associative A1
the four axioms are satisfied therefore {S, ∗} is a group
the group is Abelian because the table is symmetric (about the leading diagonal) A1
[5 marks]
A3
Note: Award A3 for all correct values, A2 for 5 correct, A1 for 4 correct and A0 otherwise.
[3 marks]
(i) the subgroups are {1, 8}; {1, 4, 7} A1A1
(ii) the cosets are {4, 5}; {2, 5, 8} A1A1
[4 marks]
METHOD 1
use of algebraic manipulations M1
and at least one result from the table, used correctly A1
x=2 A1
x=7 A1
METHOD 2
testing at least one value in the equation M1
obtain x=2 A1
obtain x=7 A1
explicit rejection of all other values A1
[4 marks]
Examiners report
The majority of candidates were able to complete the Cayley table correctly.
Generally well done. However, it is not good enough for a candidate to say something along the lines of 'the operation is closed or that inverses exist by looking at the Cayley table'. A few candidates thought they only had to prove commutativity.
Often well done. A few candidates stated extra, and therefore incorrect subgroups.
The majority found only one solution, usually the obvious x=2, but sometimes only the less obvious x=7.
Syllabus sections
- 16M.3srg.hl.TZ0.1b: Show that {S, ∗} is an Abelian group.
- 16M.3srg.hl.TZ0.1c: Determine the orders of all the elements of {S, ∗}.
- 16M.3srg.hl.TZ0.1d: (i) Find the two proper subgroups of {S, ∗}. (ii) Find the coset...
- 16M.3srg.hl.TZ0.1e: Solve the equation 2∗x∗4∗x∗4=2.
- 16M.3srg.hl.TZ0.2a: Show that R is an equivalence relation.
- 16M.3srg.hl.TZ0.2b: Given that n=2 and p=7, determine the first four members of each of the four...
- 16M.3srg.hl.TZ0.3: The group {G, ∗} is Abelian and the bijection f: G→G is...
- 16M.3srg.hl.TZ0.4a: Prove that f is an injection.
- 16M.3srg.hl.TZ0.5: The group {G, ∗} is defined on the set G with binary operation \( *...
- 16M.3srg.hl.TZ0.4b: (i) Prove that f is a surjection. (ii) Hence, or otherwise, write down the...
- 17N.3srg.hl.TZ0.5b: Prove that Ker(f) is a subgroup of {G, ∗}.
- 17N.3srg.hl.TZ0.5a: Prove that f(eG)=eH.
- 17N.3srg.hl.TZ0.4d: Show that each element a∈S has an inverse.
- 17N.3srg.hl.TZ0.4c: Show that 2 is the identity element.
- 17N.3srg.hl.TZ0.4b.i: Show that the operation ∗ on the set S is commutative.
- 17N.3srg.hl.TZ0.4a: Show that x∗y∈S for all x, y∈S.
- 17N.3srg.hl.TZ0.3b: Determine the equivalence class of R containing the element (1, 2) and...
- 17N.3srg.hl.TZ0.3a: Show that R is an equivalence relation.
- 17N.3srg.hl.TZ0.2b.ii: In the context of the distributive law, describe what the result in part (b)(i) illustrates.
- 17N.3srg.hl.TZ0.2b.i: For sets P, Q and R, verify that...
- 17N.3srg.hl.TZ0.2a.ii: Represent the following set on a Venn diagram, A∩(B∪C).
- 17N.3srg.hl.TZ0.2a.i: Represent the following set on a Venn diagram, AΔB, the symmetric difference of...
- 17N.3srg.hl.TZ0.1c: Find the left cosets of K in {G, ×18}.
- 17N.3srg.hl.TZ0.1b: Write down the elements in set K.
- 17N.3srg.hl.TZ0.1a.ii: State whether or not {G, ×18} is cyclic, justifying your answer.
- 17N.3srg.hl.TZ0.1a.i: Find the order of elements 5, 7 and 17 in {G, ×18}.
- 17M.3srg.hl.TZ0.4d: Show that the groups {Z, ∗} and...
- 17M.3srg.hl.TZ0.4c: Find a proper subgroup of {Z, ∗}.
- 17M.3srg.hl.TZ0.4b: Show that there is no element of order 2.
- 17M.3srg.hl.TZ0.4a: Show that {Z, ∗} is an Abelian group.
- 17M.3srg.hl.TZ0.3b: Hence write down the inverse function f−1(x, y).
- 17M.3srg.hl.TZ0.3a: Show that f is a bijection.
- 17M.3srg.hl.TZ0.2b: Determine the number of equivalence classes of S.
- 17M.3srg.hl.TZ0.2a.ii: Determine the equivalence classes of R.
- 17M.3srg.hl.TZ0.1b.ii: Hence by considering A∩(B∪C), verify that in this case the operation ∩...
- 17M.3srg.hl.TZ0.1b.i: Write down all the elements of A∩B, A∩C and B∪C.
- 17M.3srg.hl.TZ0.1a.ii: Determine the symmetric difference, AΔB, of the sets A and B.
- 17M.3srg.hl.TZ0.1a.i: Write down all the elements of A and all the elements of B.
- 15N.3srg.hl.TZ0.5c: Prove that {Ker(f), +} is a subgroup of...
- 15N.3srg.hl.TZ0.5b: Find the kernel of f.
- 15N.3srg.hl.TZ0.5a: Prove that the function f is a homomorphism from the group...
- 15N.3srg.hl.TZ0.4c: Find the order of each element in T.
- 15N.3srg.hl.TZ0.4b: Prove that {T, ∗} forms an Abelian group.
- 15N.3srg.hl.TZ0.4a: Copy and complete the following Cayley table for {T, ∗}.
- 15N.3srg.hl.TZ0.3d: (i) Find the maximum possible order of an element in {H, ∘}. (ii)...
- 15N.3srg.hl.TZ0.3c: Find (i) p∘p; (ii) the inverse of p∘p.
- 15N.3srg.hl.TZ0.3b: State the identity element in {G, ∘}.
- 15N.3srg.hl.TZ0.3a: Find the order of {G, ∘}.
- 15N.3srg.hl.TZ0.2c: The relation R is defined for a, b∈R so that aRb if and...
- 15N.3srg.hl.TZ0.2b: The relation R is defined for a, b∈R so that aRb if and...
- 15N.3srg.hl.TZ0.1: Given the sets A and B, use the properties of sets to prove that...
- 12M.3srg.hl.TZ0.1a: Associativity and commutativity are two of the five conditions for a set S with the binary...
- 12M.3srg.hl.TZ0.1b: The Cayley table for the binary operation ⊙ defined on the set T = {p, q, r, s,...
- 12M.3srg.hl.TZ0.2a: Given that R=(P∩Q′)′ , list the elements of R .
- 12M.3srg.hl.TZ0.2b: For a set S , let S∗ denote the set of all subsets of S , (i) find \({P^ *...
- 12M.3srg.hl.TZ0.3a: Show that R is an equivalence relation.
- 12M.3srg.hl.TZ0.3b: Find the equivalence class containing 0.
- 12M.3srg.hl.TZ0.3c: Denote the equivalence class containing n by Cn . List the first six elements of C1.
- 12M.3srg.hl.TZ0.3d: Denote the equivalence class containing n by Cn . Prove that Cn=Cn+7 for all...
- 12M.3srg.hl.TZ0.4b: The set S is finite. If the function f:S→S is injective, show that f is surjective.
- 12M.3srg.hl.TZ0.5a: (i) Show that ghg−1 has order 2 for all g∈G. (ii) Deduce that gh...
- 12N.3srg.hl.TZ0.1a: Decide, giving a proof or a counter-example, whether xRy⇔x+y>7...
- 12N.3srg.hl.TZ0.1d: Decide, giving a proof or a counter-example, whether...
- 12N.3srg.hl.TZ0.1b: Decide, giving a proof or a counter-example, whether...
- 12N.3srg.hl.TZ0.1c: Decide, giving a proof or a counter-example, whether xRy⇔xy>0...
- 12N.3srg.hl.TZ0.3e: (i) State the identity element for {P(S), Δ}. (ii) Write down...
- 12N.3srg.hl.TZ0.1e: One of the relations from parts (a), (b), (c) and (d) is an equivalence relation. For this...
- 12N.3srg.hl.TZ0.3a: Write down all four subsets of A .
- 12N.3srg.hl.TZ0.3b: Construct the Cayley table for P(A) under Δ .
- 12N.3srg.hl.TZ0.3c: Prove that {P(A), Δ} is a group. You are allowed to...
- 12N.3srg.hl.TZ0.3d: Is {P(A), Δ} isomorphic to {Z4, +4}...
- 12N.3srg.hl.TZ0.3f: Explain why {P(S), ∪} is not a group.
- 12N.3srg.hl.TZ0.3g: Explain why {P(S), ∩} is not a group.
- 12N.3srg.hl.TZ0.4a: Simplify c2∗3c4 .
- 12N.3srg.hl.TZ0.4b: State the identity element for G under ∗.
- 12N.3srg.hl.TZ0.4c: For x∈G find an expression for x−1 (the inverse of x under ∗).
- 12N.3srg.hl.TZ0.4d: Show that the binary operation ∗ is commutative on G .
- 12N.3srg.hl.TZ0.4e: Show that the binary operation ∗ is associative on G .
- 12N.3srg.hl.TZ0.4g: Show that G is closed under ∗.
- 12N.3srg.hl.TZ0.4h: Explain why {G,∗} is an Abelian group.
- 08M.3srg.hl.TZ1.1: (a) Determine whether or not ∗ is (i) closed, (ii) commutative, (iii) ...
- 08M.3srg.hl.TZ1.2: (a) Find the range of f . (b) Prove that f is an injection. (c) Taking the...
- 08M.3srg.hl.TZ1.3: (a) Find the six roots of the equation z6−1=0 , giving your answers in the...
- 08M.3srg.hl.TZ1.4: (a) Show that R is an equivalence relation. (b) Describe, geometrically, the...
- 08M.3srg.hl.TZ1.5: Let p=2k+1, k∈Z+ be a prime number and let G be the...
- 08M.3srg.hl.TZ2.1: (a) Draw the Cayley table for the set of integers G = {0, 1, 2, 3, 4, 5} under addition...
- 08M.3srg.hl.TZ2.2a: Below are the graphs of the two functions F:P→Q and g:A→B...
- 08M.3srg.hl.TZ2.2b: Given two functions h:X→Y and k:Y→Z . Show that (i) if both h and...
- 08M.3srg.hl.TZ2.4a: The relation aRb is defined on {1, 2, 3, 4, 5, 6, 7, 8, 9} if and only if ab is the square of...
- 08M.3srg.hl.TZ2.4b: Given the group (G, ∗), a subgroup (H, ∗) and...
- 08M.3srg.hl.TZ2.5: (a) Write down why the table below is a Latin...
- 08M.3srg.hl.TZ2.3: Prove that (A∩B)∖(A∩C)=A∩(B∖C) where A, B and C are...
- 08N.3srg.hl.TZ0.1: A, B, C and D are subsets of Z...
- 08N.3srg.hl.TZ0.2: A binary operation is defined on {−1, 0, 1}...
- 08N.3srg.hl.TZ0.5: Three functions mapping Z×Z→Z are defined...
- 08N.3srg.hl.TZ0.3: Two functions, F and G , are defined on A=R∖{0, 1}...
- 08N.3srg.hl.TZ0.4: Determine, giving reasons, which of the following sets form groups under the operations given...
- 11M.3srg.hl.TZ0.1a: Copy and complete the following operation table.
- 11M.3srg.hl.TZ0.1b: (i) Show that {S , ∗} is a group. (ii) Find the order of each element of {S ,...
- 11M.3srg.hl.TZ0.1c: The set T is defined by {x∗x:x∈S}. Show that {T , ∗} is a subgroup of {S...
- 11M.3srg.hl.TZ0.2a: A \ B ;
- 11M.3srg.hl.TZ0.3a: Show that R is an equivalence relation.
- 11M.3srg.hl.TZ0.4: The function...
- 11M.3srg.hl.TZ0.5b: Consider the group G , of order 4, which has distinct elements a , b and c and the identity...
- 11M.3srg.hl.TZ0.2b: AΔB .
- 11M.3srg.hl.TZ0.3b: Identify the three equivalence classes.
- 11M.3srg.hl.TZ0.5a: Given that p , q and r are elements of a group, prove the left-cancellation rule, i.e....
- 09M.3srg.hl.TZ0.1: (a) Show that {1, −1, i, −i} forms a group of complex numbers G under...
- 09M.3srg.hl.TZ0.2a: (i) Show that ∗ is commutative. (ii) Find the identity element. (iii) ...
- 09M.3srg.hl.TZ0.2b: The binary operation ⋅ is defined on R as follows. For any elements a...
- 09M.3srg.hl.TZ0.3: The relation R is defined on Z×Z such that...
- 09M.3srg.hl.TZ0.4: (a) Show that f:R×R→R×R defined...
- 09M.3srg.hl.TZ0.5: Prove that set difference is not associative.
- 09N.3srg.hl.TZ0.1: The binary operation ∗ is defined on the set S = {0, 1, 2, 3}...
- 09N.3srg.hl.TZ0.2: The function f:[0, ∞[→[0, ∞[ is defined by...
- 09N.3srg.hl.TZ0.3: The relations R and S are defined on quadratic polynomials P of the...
- 09N.3srg.hl.TZ0.5: Let {G , ∗} be a finite group of order n and let H be a non-empty subset of G . (a) ...
- SPNone.3srg.hl.TZ0.1a: The relation R is defined on Z+ by aRb if and only if ab is even. Show that...
- SPNone.3srg.hl.TZ0.1b: The relation S is defined on Z+ by aSb if and only if...
- SPNone.3srg.hl.TZ0.2c: ∗ is distributive over ⊙ ;
- SPNone.3srg.hl.TZ0.2a: ⊙ is commutative;
- SPNone.3srg.hl.TZ0.2b: ∗ is associative;
- SPNone.3srg.hl.TZ0.2d: ⊙ has an identity element.
- SPNone.3srg.hl.TZ0.3a: (i) Write down the Cayley table for {G, ×7} . (ii) ...
- SPNone.3srg.hl.TZ0.3b: The group {K, ∘} is defined on the six permutations of the integers 1,...
- SPNone.3srg.hl.TZ0.4: The groups {K, ∗} and {H, ⊙} are defined by the...
- SPNone.3srg.hl.TZ0.5: Let {G, ∗} be a finite group and let H be a non-empty subset of G . Prove...
- 10M.3srg.hl.TZ0.3: (a) Consider the set A = {1, 3, 5, 7} under the binary operation ∗, where ∗...
- 10M.3srg.hl.TZ0.4: The permutation p1 of the set {1, 2, 3, 4} is defined...
- 10M.3srg.hl.TZ0.5: Let G be a finite cyclic group. (a) Prove that G is Abelian. (b) Given that a is a...
- 10M.3srg.hl.TZ0.1: The function f:R→R is defined...
- 10N.3srg.hl.TZ0.1: Let R be a relation on the set Z such that...
- 10N.3srg.hl.TZ0.2a: Let...
- 10N.3srg.hl.TZ0.2b: P is the set of all polynomials such that...
- 10N.3srg.hl.TZ0.2c: Let h:Z→Z+,...
- 10N.3srg.hl.TZ0.4: Set...
- 10N.3srg.hl.TZ0.5: Let {G, ∗} be a finite group that contains an element a (that is not the...
- 13M.3srg.hl.TZ0.1b: is commutative;
- 13M.3srg.hl.TZ0.1c: is associative;
- 13M.3srg.hl.TZ0.2a: Copy and complete the following Cayley table for this binary operation.
- 13M.3srg.hl.TZ0.2c: Show that a new set G can be formed by removing one of the elements of S such that...
- 13M.3srg.hl.TZ0.2d: Determine the order of each element of {G, ×14}.
- 13M.3srg.hl.TZ0.2e: Find the proper subgroups of {G, ×14}.
- 13M.3srg.hl.TZ0.4b: Show that the equivalence defining R can be written in the...
- 13M.3srg.hl.TZ0.4c: Hence, or otherwise, determine the equivalence classes.
- 13M.3srg.hl.TZ0.1a: is closed;
- 13M.3srg.hl.TZ0.1d: has an identity element.
- 13M.3srg.hl.TZ0.2b: Give one reason why {S, ×14} is not a group.
- 13M.3srg.hl.TZ0.3a: (i) Sketch the graph of f. (ii) By referring to your graph, show that f is a bijection.
- 13M.3srg.hl.TZ0.3b: Find f−1(x).
- 13M.3srg.hl.TZ0.4a: Show that R is an equivalence relation.
- 13M.3srg.hl.TZ0.5: H and K are subgroups of a group G. By considering the four group axioms, prove that...
- 11N.3srg.hl.TZ0.1a: Consider the following Cayley table for the set G = {1, 3, 5, 7, 9, 11, 13, 15} under the...
- 11N.3srg.hl.TZ0.1b: The Cayley table for the set...
- 11N.3srg.hl.TZ0.1c: Show that {G, ×16} and {H, ∗} are not...
- 11N.3srg.hl.TZ0.1d: Show that {H, ∗} is not cyclic.
- 11N.3srg.hl.TZ0.2a: Determine, using Venn diagrams, whether the following statements are true. (i) ...
- 11N.3srg.hl.TZ0.2b: Prove, without using a Venn diagram, that A∖B and B∖A are...
- 11N.3srg.hl.TZ0.4a: Show that R is an equivalence relation.
- 11N.3srg.hl.TZ0.4b: The Cayley table for G is shown below. The subgroup H is given as...
- 11N.3srg.hl.TZ0.5a: Show that if both f and g are injective, then g∘f is also injective.
- 11N.3srg.hl.TZ0.5b: Show that if both f and g are surjective, then g∘f is also surjective.
- 11N.3srg.hl.TZ0.5c: Show, using a single counter example, that both of the converses to the results in part (a)...
- 12M.3srg.hl.TZ0.4a: The function g:Z→Z is defined by...
- 12M.3srg.hl.TZ0.4c: Using the set Z+ as both domain and codomain, give an example of an...
- 14M.3srg.hl.TZ0.2a: (i) Write down the six smallest non-negative elements of S. (ii) Show that...
- 14M.3srg.hl.TZ0.2b: The relation R is defined on S by s1Rs2 if...
- 14M.3srg.hl.TZ0.3a: (i) Sketch the set X×Y in the Cartesian plane. (ii) Sketch the set...
- 14M.3srg.hl.TZ0.4b: (i) Prove that the kernel of f, K=Ker(f), is closed under the...
- 14M.3srg.hl.TZ0.1: The binary operation Δ is defined on the set S= {1, 2, 3, 4, 5} by the...
- 14M.3srg.hl.TZ0.3b: Consider the function f:X×Y→R defined by f(x, y)=x+y...
- 14M.3srg.hl.TZ0.4c: (i) Prove that gkg−1∈K for all g∈G, k∈K. (ii) ...
- 13N.3srg.hl.TZ0.2a: (i) Prove that G is cyclic and state two of its generators. (ii) Let H be...
- 13N.3srg.hl.TZ0.2b: State, with a reason, whether or not it is necessary that a group is cyclic given that all...
- 13N.3srg.hl.TZ0.1: Consider the following functions ...
- 13N.3srg.hl.TZ0.4: Let (H, ∗) be a subgroup of the group \((G,{\text{ }} *...
- 13N.3srg.hl.TZ0.5: (a) Given a set U, and two of its subsets A and B, prove...
- 14M.3srg.hl.TZ0.4a: Prove that f(eG)=eH, where eG is the identity element in G and...
- 15M.3srg.hl.TZ0.3b: Hence prove that R is reflexive.
- 15M.3srg.hl.TZ0.4a: Prove that: (i) f is an injection, (ii) g is a surjection.
- 15M.3srg.hl.TZ0.2a: Find the element e such that e∗y=y, for all y∈S.
- 15M.3srg.hl.TZ0.2b: (i) Find the least solution of x∗x=e. (ii) Deduce that (S, ∗)...
- 15M.3srg.hl.TZ0.3d: Find the set of all y for which 3Ry.
- 15M.3srg.hl.TZ0.3e: Using your answers for (c) and (d) show that R is not symmetric.
- 15M.3srg.hl.TZ0.1a: Complete the following Cayley table [5 marks]
- 15M.3srg.hl.TZ0.1b: (i) State the inverse of each element. (ii) Determine the order of each element.
- 15M.3srg.hl.TZ0.1c: Write down the subgroups containing (i) r, (ii) u.
- 15M.3srg.hl.TZ0.2c: Determine whether or not e is an identity element.
- 15M.3srg.hl.TZ0.3a: Show that the product of three consecutive integers is divisible by 6.
- 15M.3srg.hl.TZ0.3c: Find the set of all y for which 5Ry.
- 15M.3srg.hl.TZ0.4b: Given that X=R+∪{0} and Y=R, choose a suitable...
- 15M.3srg.hl.TZ0.5a: Show that (G, +) forms a group where + denotes addition on...
- 15M.3srg.hl.TZ0.5b: Assuming that (H, +) forms a group, show that it is a proper subgroup of...
- 15M.3srg.hl.TZ0.5c: The mapping ϕ:G→G is given by ϕ(g)=g+g, for g∈G. Prove that...
- 14N.3srg.hl.TZ0.1b: Find the order of each of the elements of the group.
- 14N.3srg.hl.TZ0.1c: Write down the three sets that form subgroups of order 2.
- 14N.3srg.hl.TZ0.5c: Let {H,∗} be a subgroup of {G,∗}. Let R...
- 14N.3srg.hl.TZ0.1a: Find the values represented by each of the letters in the table.
- 14N.3srg.hl.TZ0.1d: Find the three sets that form subgroups of order 4.
- 14N.3srg.hl.TZ0.2b: Prove that f is not a surjection.
- 14N.3srg.hl.TZ0.2a: Prove that f is an injection.
- 14N.3srg.hl.TZ0.3a: Two members of A are given by p=(1 2 5) and...
- 14N.3srg.hl.TZ0.4c: Given that f(x∗y)=p, find f(y).
- 14N.3srg.hl.TZ0.3b: State a permutation belonging to A of order (i) 4; (ii) 6.
- 14N.3srg.hl.TZ0.3c: Let P= {all permutations in A where exactly two integers change position}, and...
- 14N.3srg.hl.TZ0.4a: Prove that for all a∈G, f(a−1)=(f(a))−1.
- 14N.3srg.hl.TZ0.4b: Let {H, ∘} be the cyclic group of order seven, and let p be a...
- 14N.3srg.hl.TZ0.5a: State Lagrange’s theorem.
- 14N.3srg.hl.TZ0.5d: Let {H,∗} be a subgroup of {G,∗} .Let R...
- 14N.3srg.hl.TZ0.5b: Verify that the inverse of a∗b−1 is equal to b∗a−1.
- 14N.3srg.hl.TZ0.5e: Let {H,∗} be a subgroup of {G,∗} .Let R...