00:01
In this question, we have been given a symmetric group s4, which is a permutation of the 4 letter and we have k is equals to 1 and the permutation 1, 2, 3, 4, 1, 3, 2, 4 and it has 1, 4, 2, 3.
00:19
It consists of these 4 permutations.
00:22
We have to show that k is a subgroup of the symmetric group s4.
00:27
So how we are going to show this since we know that order of s4 is equals to 4 factorial it is equals to 24 order of s4 mod k it will be 24 over 4 k has 4 element so it is equals to 6.
00:46
Now what i will do, i will let one element 1, 2, 3 which belongs to s4, correct and i will take this as g which is 1, 2, 3.
00:57
It will permute on k to generate the following elements, permute on k to give the following set.
01:07
So 1, 2, 3 when it permutes with 1, it will be just 1, 2, 3 only.
01:11
1, 2, 3 permutes with 1, 2, 3, 4, it will give you 1, it will give you 3, 4 only.
01:21
What i am doing is here 1, 2, 3 is getting permuted with 1, 2, 3, 4.
01:28
So solving this we get this to be just 3, 4...