Mathematical headaches? Problem solved!
Hi, I'm Colin, and I'm here to help you make sense of maths
Mathematical headaches? Problem solved!
Hi, I'm Colin, and I'm here to help you make sense of maths
A reader asks: I know that a square matrix $\mathbf{M}$ maps point $\mathbf{x}$ to point $\mathbf{y}$. Do I have enough information to work out $\mathbf{M}$? In a word: no, unless you're working in one dimension! In general, to work out a square transformation matrix in $n$ dimensions, you need to
Read More →"A $z$-score of 1.4," said the student, reaching for his tables. "0.92," said the Mathematical Ninja, without skipping a beat. "0.9192," said the student, with a hint of annoyance. "How on earth..." "Oh, it's terribly simple," said the Mathematical Ninja. "It turns out, for smallish values of $z$, the normal
Read More →In this month's Wrong, But Useful, @icecolbeveridge (Colin Beveridge in real life) and @reflectivemaths (Dave Gale when he's at home)... ... completely forget about the Maths Book Club, which was going on during the recording; ... get all excited about the MathsJam conference on the weekend of November 2nd-3rd ...
Read More →"You would not be certain that $17 \times 24$ is not 568." - Daniel Kahneman, Thinking Fast And Slow Thanks to Alice for pointing out that yes, she bloody well would. Most people under 50 in the UK would reach for a calculator, or possibly a pen and paper to
Read More →"... Evidently not," said the student, with a look of sheer terror that was music to the Mathematical Ninja's eyes. He smiled a nasty smile. "No," he said, "you categorically do not add probabilities as you go through the tree." "You... multiply?" The student was cautious. The Mathematical Ninja hadn't
Read More →Ask virtually any maths teacher what $\sec(\alpha)$ means, the chances are they'll say "it's $\frac{1}{\cos(\alpha)}$," without missing a beat. Ask them what it means geometrically... well, I don't want to speak for the teaching profession as a whole, but I'd have been stumped until the other day. As with the
Read More →This is an odd, out-of-sequence post, but I just saw this and thought it needed sharing. - John Halpern in real life - is one of my heroes. I'd rate him comfortably among the top five crossword compilers in the UK (possibly the world), and not just because he has
Read More →Chair: If 'good' requires pupil performance to exceed the national average, and if all schools must be good, how is this, how is this mathematically possible? Michael Gove: By getting better all the time. Chair: So it is possible, is it? Michael Gove: It is possible to get better all
Read More →In honour of 's birthday this week, here's a post with a vaguely Douglas-Adams-related theme. The student looked at the Mathematical Ninja and decided this was a moment where reaching for the calculator would be appropriate. "$\frac{29}{42}$..." she said aloud. "0.69," said the Mathematical Ninja. She threw the calculator down
Read More →At a recent MathsJam, there was a puzzle. This is nothing out of the ordinary. It went something like: If an absent-minded professor takes his umbrella into a classroom, there's a probability of $\frac{1}{4}$ that he'll absent-mindedly leave it there. One day, he sets off with his umbrella, teaches in
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