This is the third and final part of the how to think about co-ordinate geometry series. Due to a failure of calendar-reading, I appreciate this is going out a few days after the C1 and C2 exams, but hey-ho. If you're relying on this blog for your revision tips, you

Read More →This is part two of a three-part series about co-ordinate geometry. In part I last week, I went into tedious detail about the equation of a line. This week, I’m going to take it a bit further and go into curves. Next week, you get to see circles. So, what

Read More →Pretty much every C1 student I’ve ever worked with has said the same thing: I don’t get the big questions at the end of the paper. The ones with the curves and the equation of a line and the tangents and the turning points — what’s that all about? So,

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Posted in algebra, circles, quadratics.

-or- matching coefficients for fun and profit I bluffed my way through completing the square at A-level. I guessed, dropped minus signs, and dropped marks all the way. It was only once I started teaching it that I figured out completing the square. Let me share it with you. Completing

Read More →A conjecture both deep and profound Needs a proof that the circle is round. In a paper by Erdős Written in Kurdish A counter-example is found. One of my favourite questions to ask students is "what's a circle?" because I get to play "so that means this is a circle!"

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