The Sunday Function

I sometimes forget that we don't all read the same blogs, and that it's good to recommend some of the fun stuff out there on the internets. So let me give a shout-out to Matt Springer at Built on Facts, who had the brilliant idea of discussing a different function every Sunday. Functions are one of those things that are as necessary to math and science as breathing, but which don't necessarily percolate into the wider world. And he (quite correctly, I think) interprets his self-imposed mandate fairly liberally, taking the time to talk about various issues in middle-level mathematics. Here are some selections from Matt's series:

• Exponential

• Arctangent

• Witch of Agnesi

• Stirling's approximation

• Continuous but almost-nowhere differentiable

Consider this an open thread to recommend other stuff we should all be reading. Or your favorite functions.