## Girls’ Angle Bulletin, Volume 8, Number 4

Volume 8, Number 4 of the Bulletin kicks off with the concluding half of our 2-part interview with Hamilton College Assistant Professor of Mathematics Courtney Gibbons.  In this second half, one of the objects she describes are the Cayley graphs of groups.  This inspired the creation of several Cayley graphs by members of Girls’ Angle, which are featured in this issue’s Math Buffet.

The cover itself also shows a Cayley graph of $S_5$.

An (18, 8)-star. What would you say is the ratio of the radius of the (18, 7)-star contained within to the (18, 8)-star?

Next, Emily and Jasmine continue their exploration of n-pointed stars.  This time, they follow-up on an observation that Emily made about the (17, 7)-star on the cover of Volume 8, Number 3.  She noticed that the (17, 7)-star contains (17, k)-stars for k = 1, 2, 3, 4, 5, and 6. Together, they not only show that this is an instance of a general phenomenon, but they also find the relationship between the sizes of such embedded stars within stars.

Anna wraps up her study of cross sections of the surface z = xy.

In Part 3 of The Derivative, we explain both the Chain Rule and the Quotient Rule along the line emphasized in this series: local linearity. We hope that the Chain Rule, especially, appears “obvious” from this point-of-view. For another take on the Chain Rule, here’s an earlier post that uses movies to explain it.

Next, Stuart Sidney, Emeritus Professor at the University of Connecticut, entertains us with curious facts about palindromic numbers.

We introduce a mathematical variant of the classic Hot Potato game that can be used as a vehicle to explore quite a few math concepts and in quite a bit of depth.

Finally, in Notes From the Club, we give a brief account of Bathsheba Grossman’s recent Support Network visit to Girls’ Angle. If you haven’t seen her mathematically inspired sculptures, you’re in for a treat. She mesmerized us for over an hour with her inspiring creations.

We hope you enjoy it!

Finally, a reminder: when you subscribe to the Girls’ Angle Bulletin, you’re not just getting a subscription to a magazine. You are also gaining access to the Girls’ Angle mentors.  We urge all subscribers and members to write us with your math questions or anything else in the Bulletin or having to do with mathematics in general. We will respond. We want you to get active and do mathematics. Parts of the Bulletin are written to induce you to wonder and respond with more questions. Don’t let those questions fade away and become forgotten. Send them to us!

We continue to encourage people to subscribe to our print version, so we have removed some content from the electronic version.  Subscriptions are a great way to support Girls’ Angle while getting something concrete back in return.  We hope you subscribe!