Posted in ninja maths, trigonometry

The Mathematical Ninja sniffed. "$4\sin(15º)$? Degrees? In my classroom?" "Uh uh sorry, sensei, I mean $4\sin\br{\piby{12}}$, obviously, I was just reading from the textmmmff." "Don't eat it all at once. Now, $4\sin\br{\piby{12}}$ is an interesting one. You know all about Ailes' Rectangle, of course, so you know that $\sin\br{\piby{12}}=\frac{\sqrt{6}-\sqrt{2}}{4}$, which

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Posted in ask uncle colin

Dear Uncle Colin, I have to work out $851 \div 37$ without pen, paper or calculator. How would you do it? - Simple Mental Arithmetic Looks Easy Hi, SMALE, and thanks for your message! I have three ways to tackle it. Brute force and estimation It's fairly obvious that the

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Posted in podcasts

In this month's episode of Wrong, But Useful, we are joined by maths communication superhero @stecks, who is Katie Steckles in real life. We discuss: Katie's numerous and various activities as a maths freelancer, including maths busking and being a mathematician-in-residence at the Stephen Lawrence Gallery at the University of

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Posted in basic maths skills

A question that frequently comes up in the insalubrious sort of place a mathematician might hang around is, what is that value of $0^0$. We generally sigh and answer that the same way every time. It was nice, then, to see someone ask a more fundamental one: what is $0

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Posted in ask uncle colin

Dear Uncle Colin, How come $0.3^{0.3} > 0.4^{0.4}$? - Puzzling Over It, Some Surprisingly Ordered Numbers Hi, POISSON, and thank you for your message! It is a bit surprising, isn't it? You would expect $x^x$ to increase everywhere, at first glance. Why it doesn't We can see that this isn't

Read More →"Cooking," said my friend Liz in a recent Facebook post, "is one of the activities where maths is most useful in my everyday life." She added this picture: I've got several reasons for wanting to share this. 1. It's pretty much a model answer Imagine you're in a GCSE exam,

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Posted in ask uncle colin

Dear Uncle Colin, I need to find the largest solution to $e^x + \sin(x)=0$ and I don't really know where to start. Any ideas? - Some Options Look Virtually Equal Hi, SOLVE, and thanks for your message! That is something we in the trade call 'not a very nice equation

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Posted in dialogue

Yes I count how many women's voices I hear in your podcast. — Rose Eveleth ▷▷ (@roseveleth) October 31, 2017 So do we. We are aware of, and unhappy about, the predominance of heterosexual, cisgendered white men in mathematics, and we want to play a part in addressing that. Since

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Posted in ask uncle colin

Dear Uncle Colin, I keep being told my work needs to be tidier, but I'm not really sure how to go about that. Do you have any suggestions? - My Exercises Skew Scruffy Hello, MESS, and thanks for your message. I totally feel your pain. In honesty, this is like

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Posted in in praise of...

"It is like a cave that seemed to be absolutely sparkling with jewels. Maths glittered like a Christmas tree at me." - Amanda Spielman, at the Education Select Committee, October 30th 2017 What an image. What an image. Caves are dark, and cold, and slightly frightening, but buried deep within,

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