I'd say derivatives/integrals being applied to velocity/acceleration/etc, and using integrals to find volumes of revolution and such, are pretty elegant.
I agree with you here, but I meant more from a process rather than application perspective.
By analogy, it's like choosing to use options / maybe monad instead of null in a service that takes input. The end service's functionality is the same regardless! (maintainability might be a different matter though, hehe)
