Posted in mechanics 1.

At the 1939 World’s Fair, San Francisco Seals catcher Joe Sprinz tried to catch a baseball dropped from the Goodyear blimp 1,200 feet overhead. Sprinz knew baseball but he hadn’t studied physics — he lost five teeth and spent three months in the hospital with a fractured jaw. - from

Read More →
Posted in algebra.

Over on reddit, noncognitivism posted a nice sequence s/he had come across: $4 + 1 = 5 = \sqrt{ (1)(2)(3)(4) + 1 }$ $(4+6) + 1 = 11 = \sqrt{ (2)(3)(4)(5) + 1}$ $(4+6+8) + 1 = 19 = \sqrt{ (3)(4)(5)(6) + 1}$ $…$ $(4+6+ … + (2k+2)) + 1

Read More →
Posted in ninja maths, probability.

For the first time anyone could remember, the Mathematical Ninja trembled with fear. He’d pulled his scary face, and it hadn’t worked: Victoria Coren Mitchell had simply said “you don’t scare me” and he had no idea what to do next. “It’s time for the wall game,” she said. “Right,”

Read More →
Posted in sport.

A reader asks: What’s the biggest lead a football team can have in the table after $n$ games? In a typical football league, teams get three points for a win, one for a draw, and none for getting beat. After, for example, one game, if one team wins and all

Read More →The brilliant @dragon_dodo has written a cartoon to explain - as if explanation were needed - of why radians are the correct way to measure angles.

Read More →There's a legend, so well-known that it's almost a cliche, about the wise man who invented chess. When asked by the great king what reward he wanted, he replied that he'd be satisfied by a chessboard full of rice: one grain on the first square, two on the second, four

Read More →
Posted in featuring peter rowlett, podcasts.

Recorded LIVE at Big MathsJam Apologies for the variable sound quality in this episode; the problems of recording live. The Wrong, But Useful tag team are joined by @peterrowlett (Peter Rowlett) Colin concedes that Dave's talk was quite clever Dave mentions the 1, 3, 2, 6 sequence (a talk by

Read More →
Posted in core 4, integration.

A student asks: I've got to work out: $\int \cosec^2(x) \cot(x) \d x$. I did it letting $u = \cosec(x)$ and got an answer -- but when I did it with $u = \cot(x)$, I got something else. What gives? Ah! A substitution question! My favourite -- and it sounds

Read More →A student asks: I know that $x^3 e^{-x}$ approaches zero as $x$ approaches infinity - I can see it from the graph - but I don't really understand why? Can you help? Of course I can! However, it's going to take us into the murky depths of analysis, and we'll

Read More →