Monday Math: So What Is a Prime?

Last time, I explained that the biggest reason why 1 isn't a prime is the Fundamental Theorem of Arithmetic. This time, I want to go over the proof of the FTA, and point out some subtleties.

( Breakdown! )

Rainy Days and Mondays

Today, we had our first candidate for the Applied Math position come in for her face-to-face interview. We ask each candidate to give a research presentation, and also to demonstrate their teaching abilities. For the latter, they are expected to step in to one of our calculus classes and teach the first half-hour of that day's lesson. (We give them the material a few days ahead of time; they don't go in completely cold.) Today's candidate began her lesson, an introduction to the derivative, in fine form, presenting the outline of a two-pronged approach... and the fire alarm went off.

We waited outside - fortunately, though damp, it was unseasonably warm - for about twenty minutes before being allowed back in. She resumed her presentation with considerable aplomb, and continued as she had begun. Alas, she was fifteen minutes late for her next appointment. Our chair had ducked out and warned the Dean that she would be late, so there was no trouble, but it was definitely a headshaking situation.