A MATH JOKE (only intelligible if you’ve taken calculus already)

So a bunch of functions were lounging around, when suddenly this crazy person barges in and yells “I’ll integrate you! I’ll differentiate you!”

All the functions scatter like crazy, and the assailant goes and differentiates and integrates a whole bunch of them, transforming them (through long arduous processes) into different functions.

Then he comes up to this one function, and differentiates him. Nothing happens. He integrates. Still no effect. “Why aren’t you scared of me?” the assailant demands. “I said I’ll integrate and differentiate you!”

The unfazed function replies rather calmly, “You can do neither to me. I’m e to the x.”