Date | May 2008 | Marks available | 3 | Reference code | 08M.1.hl.TZ0.2 |
Level | HL only | Paper | 1 | Time zone | TZ0 |
Command term | Solve | Question number | 2 | Adapted from | N/A |
Question
The group {G,∗} is defined on the set G={1,2,3,4,5,6} where ∗ denotes multiplication modulo 7.
Draw the Cayley table for {G,∗} .
(i) Determine the order of each element of {G,∗} .
(ii) Find all the proper subgroups of {G,∗} .
Solve the equation x∗6∗x=3 where x∈G .
Markscheme
A3
Note: Award A2 for 1 error, A1 for 2 errors, A0 for 3 or more errors.
[3 marks]
(i) We first identify 1 as the identity (A1)
Order of 1=1
Order of 2=3
Order of 3=6
Order of 4=3
Order of 5=6
Order of 6=2 A3
Note: Award A2 for 1 error, A1 for 2 errors, A0 for more than 2 errors.
(ii) {1,6} ; {1,2,4} A1A1
[6 marks]
The equation is equivalent to
6∗x∗x=3 M1
x∗x=4
x=2 or 5 A1A1
[3 marks]