## How my students learned to do delta-epsilon proofs

I previously mentioned that my students did much better on $\delta$$\epsilon$ proofs than I expected. So I asked them how they came to know how to do them in a clicker question. Here were their options:

1. Calculus
2. Foundations (our introduction to proofs course)
3. This class (complex analysis); I figured it out while preparing the presentations.
4. This class (complex analysis); another student taught me and now I understand.
5. This class (complex analysis), but I don’t understand them. I basically just did what another student told me to do.
6. You must be mistaken, Bret. I do not know how to do $\delta$-$\epsilon$ proofs.
7. Other

About 29% said they learned in our introduction to proofs course, maybe 42% said “Other,” which was a combination of “real analysis” and “the internet,” and the remaining was evenly spread over the other options.