March, 2014

There’s More Than One Way To Do It: Direct and Inverse Proportion

$y$ is directly proportional to $x^3$, you say? And when $x = 4$, $y = 72$? Well, then. The traditional method is to say: $y = kx^3$ and substitute in what you know. $72 = 64k$ $k = \frac{72}{64} = \frac{9}{8}$ That gives $y = \frac98 x^3$. Easy enough. But

Wrong, But Useful: Episode 13

A special anniversary episode where @reflectivemaths (Dave Gale) and I pick the brains of two special guests: Abel prize nominee @samuel_hansen (Samuel Hansen) and @peterrowlett (Dr Peter Rowlett, surprisingly). "I think we should conclude that an argument has gone on long enough when Samuel Hansen is the voice of conciliation"

A riposte to the Mathematical Ninja!

@srcav wasn't going to take that argument lying down! The Ninja looked smug. He thought that was it, game over. I thought it had been a sneaky trick he’d pulled with the Ninja Bread, but I couldn’t change it now. I finally pulled my mouth apart and took a big

The Equation of a Straight Line: Secrets of the Mathematical Ninja

"Who DARES to challenge the Mathematical Ninja?" he bellowed. "It is I," said the challenger. "@srcav, but Cav in real life." "Oh!" said the Mathematical Ninja. "Hello there, old chap, I was expecting someone else. Come in, I'll put the kettle on." "Much obliged," said Cav. The challenge, which Cav

Is there a tangent rule?

There's a natural question, when you learn about the sine and cosine rules: "Is there a tan rule?" The answer to that is yes - yes, there is a tan rule. The natural follow-up is "Why don't we learn it?" Let me explain why not! Here's the tangent rule in

Is there a tangent rule?

There's a natural question, when you learn about the sine and cosine rules: "Is there a tan rule?" The answer to that is yes - yes, there is a tan rule. The natural follow-up is "Why don't we learn it?" Let me explain why not! Here's the tangent rule in

Is there a tangent rule?

There's a natural question, when you learn about the sine and cosine rules: "Is there a tan rule?" The answer to that is yes - yes, there is a tan rule. The natural follow-up is "Why don't we learn it?" Let me explain why not! Here's the tangent rule in

$6\times4$ or $4\times6$?

Every so often, a question that comes up that looks incredibly trivial, but - no matter how much each side protests that the preference doesn't really matter - sets down clear divides in the maths community. My podcasting partner in crime-fighting @reflectivemaths (Dave Gale in real life) stumble upon such

Sam Warburton’s Dilemma

There are six minutes to play in the last Autumn international, and Australia are leading Wales by 30 points to 26. Australia, however, have just conceded a penalty in front of the posts, leaving the Welsh captain, Sam Warburton, with a dilemma: should he kick at goal (and take a

A student asks: I'm currently preparing for my GCSE mocks. I started looking over quadratic expressions and factorisation and it just blew me away - I get stuck trying to work it out with negatives! First things first: thanks for asking for help. You're not alone: factorising quadratics can be