Composition of functions and stuff

[polarbears]

1. Show that the set {f:R-{0,1}\rightarrow R-{0,1}}, of functions under composition, is isomorphic to S _{3}
f_{1} = x
f_{2} = 1 - x
f_{3} = \frac {1}{x}
f_{4} = 1 - \frac {1}{x}
f_{5} = \frac {1}{1 - x}
f_{6} = \frac {x}{x - 1}

Homework Equations

The Attempt at a Solution

I don't really understand what the problem is asking

 

[lanedance]

hey polarbears - there might be a smarter way, but I would start by having a look at the group S3, eg. all permutations of a set of 3 elements & see if you can find a 1-1 correspeondance between elements of S3 & the functions you are given, that is preserved under multiplication (in this case composition of functions)

for example, it should be clear that:
f₁(f_n(x))= f_n(x), for any n, which makes it a good candidate for the identity element

info on S3 is here, have a look at the mult table in particular
http://groupprops.subwiki.org/wiki/Symmetric_group:S3

 

[fmam3]

Is this a question from the Gilbert book?