Due to resource constraints, I wasn't able to do this as an activity, so I combined it with the Finding Coefficients activity and used it as a demo/interactive lecture to wrap-up that activity. I had them turn in a reflection which asked the following:

1. What does it mean to write a series expansion around the point a?
2. Briefly describe in words how to expand a series approximation for a function, correct to fourth order.
3. Write down something that you would like to remember from this activity and/or any questions that it raised.

In looking through responses, there were a few things that I was able to emphasize/re-iterate as we moved on to the power series for dipole activity:

• There was a lot of language about approximation, so I took the opportunity to reiterate the difference between the infinite series as a representation of the function and a truncated series as an approximation
• There was still a lot of confusion about what “4th order” meant and it came up again when we were doing power series for the dipole
• One of the most common questions was in regard to the usefulness of power series, which was a nice set-up for a discussion of multipole expansion.

The worksheet is pretty self explanatory and students can jump right in with little introduction. However, a few students seemed unsure of the larger point of the activity. Next time, I will ask them to spend a few min just looking at the worksheet, trying to answer the questions, “What is the point of the is worksheet? What are you supposed to learn from doing this?”