Moonlighting agony uncle Professor Dirichlet answers your personal problems. Want the prof’s help? Send your problems to deardirichlet@chalkdustmagazine.com.
Dear Dirichlet,
The annual village fete is fast approaching, and every year I embarrass myself at `guess the number of sweets in the jar’. My exasperated wife ends up telling me to just say a number, and I always panic. Last year my guess was $\mathrm{i} – \text{π}$. Maybe I was just hungry.
— Hungry hungry hippo, Gospel Oak
Dirichlet says:
It’s important not to get stressed in these situations. Sure, you have countless choices, but you’ve just got to think rationally, stay positive: don’t make it overly complex. The sweets in the jar stand is an integral part of any fete, and who wouldn’t want some tasty gummy d’Alemberts, strawberry Lovelaces or shilbert lemons? If in doubt, round up, and you can’t go too far wrong.
Dear Dirichlet,
I recently started my own business selling standard issue clothing for hospital staff. I get lots of orders but every month I somehow get countless complaints from customers who never receive anything. What can I do?
— Scrubbing up, Warwick
Dirichlet says:
I’m afraid the all or nothing delivery is an inherent problem for a uniform distribution business. The normal concerns businesses have are that all customers receive something but hardly anyone receives everything they need. To increase your probability of success, simply create more stock and distribute it more widely. Else send partially complete orders to more people, but that could lead to more complaints. At least you’re doing much better than my friend Dirac. His company, Delta, always produced the full quota for orders, but it would get sent out in one go to a single address. His distribution just didn’t function.
Dear Dirichlet,
I run a chain of stores that imports a lot from Europe. I’m sure that Brexit will be a disaster for us and I’ve been fighting loudly to try and stop it. However, it appears that my campaigning has led to my stores in Basildon, Rochester and the Kran National Park in Togo suddenly not making any profit. Any idea why?
— Not another one, Snettisham
Dirichlet says:
After marking your store locations on the antique globe I keep in my study, I’m afraid I have bad news. Your stores with zeros as their profits all lie on the line half-a-degree east. It does appear that your valiant efforts have condemned your business to suffer in this way: a direct corollary of the Remain hypothesis.
Dear Dirichlet,
I am not sure if you have a floral maths section but I would like to enter this photo I took in my garden today. What do you grow in your garden?
— Green fingers, Outdoors
Dirichlet says:
I always enjoy receiving pictures of flowers. At my country house, I grow hya-sinh and cro-cosh-es. In the city, I just keep herbs: some sparsley, teragon, and a small pot of Sage (because it’s cheaper than Mathematica). In fact, I recently uploaded some photos of them to the ar-Chive. I did try growing integeraniums once but they were eaten by the badgers.
Dear Dirichlet,
My sister has recently given birth to twin daughters. I’m excited to be visiting them at home next week and meeting them for the first time but I’m worried I will struggle to tell the twins apart. Any tips?
— Aunt you happy to see me, Sandwell
Dirichlet says:
A twin $f:\mathbb{R}\to\mathbb{R}$ is differentiable at home, $\Omega\in\mathbb{R}$, if the derivative
\[f'(\Omega) = \lim_{h\to0}\frac{f(\Omega+h)-f(\Omega)}{h}\text{ exists.}\]