# With apologies to Professor Rubin

Last week I wrote a couple of blogs, as a way of explaining to myself, about the way in which a Taylor expansion could approximate for a function and in doing so, quoted L’Hospital’s rule.

Professor Paul A. Rubin, of Michigan State University (to whom I now owe a whole night of drinks), pulled me up about my use of L’Hospital’s rule.

I have to confess I did not quite follow his point – but having watched the video below, I now do: L’Hospital’s rule solves $\frac{f(x)}{g(x)}$ for a particular point, not for the whole domain of $x$.

# Sexy Maths…

Image via Wikipedia

Paul A. Rubin – “apostate mathematician and Professor of Management Science at Michigan State University” – commented on the blog post below about P=NP and so naturally enough I had a look at his blog and the most recent item is something of a corker … “

In it Professor Rubin lists three prominent actresses who are/were also scientists with serious achievements to their name and says that he already knew about one of them … Danica McKellar.

But even as I read it I realised that while I didn’t know about her, I did (vaguely) know about Hedy Lamarr – I think I may have read about her in Andrew Tannenbaum’s Computer Networks - which I read large chunks of earlier this academic year. As I recall her proposal on frequency-hopping was not taken seriously by the US Navy at the time (during the war), which proved to be a pretty big mistake. It’s now widely used in all sorts of wireless communications.

Anyway, I challenged Professor Rubin’s challenge to me about the potential brokenness of public key encryption if P = NP before I realised he was likely someone with the intellectual firepower to destroy me an instant – so I hope he will take this link back to his blog as a peace offering.

Plus, writing this is more interesting (what isn’t?) than constructing Unified Process use cases for my object orientated design and programming class…