August, 2014

The Mathematical Pirate’s Guide to Factorising Cubics

“Yarr,” said the Mathematical Pirate. “Ye’ll have plundered a decent calculator, of course?” “Er… well, I bought it from Argos, but… aye, cap’n! A Casio fx-83 GT PLUS!” “A fine calculator,” said the Mathematical Pirate. “One that offers you at least three ways to factorise cubics.” “Really!? I thought you

In a class recently, I came across a circle theorem problem I’m certain I’ve seen before, but that I didn’t know off the top of my head how to solve. Here it is; have a go at it if you’d like to. ￼ The examiners’ expectation was clearly that the

Arccosine: secrets of the Mathematical Ninja

“$\cos^{-1}(0.93333)$, said the student. A GCSE student, struggling a little; the Mathematical Ninja bit his tongue rather than correct him to $\arccos$ or to $\frac {14}{15}$; he also accepted, grudgingly, the answer was going to be in degrees. “Maybe 21 bad degrees?” “21.04”, said the student. “Not too terrible.” “I

BBC Sport’s anti-smartness bias

“[James McEvoy] is an unashamed geek – he was reading a book on physics, as you do, to see if it could improve his performance.” – Radio 5 swimming commentator “You need some kind of accountancy degree to work out what each of them needs to do in the final

Wrong, But Useful: Episode 17

Didn’t July seem to go on for ever? What’s that? Oh. Um, yeah, delayed Episode 17 because @reflectivemaths (Dave Gale) decided a family holiday was more important than your listening pleasure. What a selfish man. This month, we talk about: Dave’s failure to send a postcard The contents of fruit-juice

Powers of $e$ revisited: Secrets of the Mathematical Ninja

The Mathematical Ninja woke up at 8:58, and opened his other eye. “$e^{12}$?” asked his alarm clock. “$160,000$,” said the Mathematical Ninja, and sat bolt upright. He leapt out of his sleeping corner, somersaulted across the room, landing in front of the whiteboard just as the student arrived. “$e^{12}$?” he

Why we lose mathematicians (a hypothesis)

This is something that struck me the other day when someone asked me about the difference between university maths and sixth-form maths: every time a student moves between educational levels, “what maths is” undergoes a dramatic change. This is based on my memories of school and is likely to be

Poissons and binomials

A student asked: What’s the link between the Poisson formula and the binomial? … and I started to cry a little bit. Infinitely many trials You use the Poisson distribution when you have events happening at a constant rate, on a continuous time-frame – as opposed to the binomial, which