# Homework Help: Symmetry groups and Caley tables

1. Aug 30, 2007

### benedwards2020

1. The problem statement, all variables and given/known data

I have a shape about the origin. It has rotational symmetry but not reflectional symmetry (its an odd star shape!).

I have to write down in standard notation the elements of the symmetry group and I have to construct a caley table under composition of symmetries.

I think I'm getting mixed up with some of the terminology here. By standard notation does it mean

S(Q) = {e, Rpi/2, Rpi,.....) etc?

And the caley table under composition symmetries, does it mean simply the table constructed with each element across the top and down the side and then calculated in the normal way?

Thanks

2. Aug 30, 2007

### matt grime

The definition of 'Standard notation' is almost certainly purely local, and definitely not standard. Sorry. You need to use whatever notation has been set in your book or lecture course.

The definition of Cayley table is precisely what you wrote.

3. Aug 30, 2007

### benedwards2020

Many thanx.... Sometimes these maths books can be a bit vague