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Andy

@andypmaths.bsky.social

A Level Maths tutor. Founder of thealevelmathstutor.co.uk

Andy @andypmaths.bsky.social · 01/06/2025

Incidentally, the example above is called a point of undulation. I find that the graph of the second derivate (purple in this graph) nicely shows how the second derivative can be zero without a change of sign.

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Andy @andypmaths.bsky.social · 14/03/2025

Rob is correct. Some bright spark at Casio thought it would be a good idea to confuse students all over the world by truncating. Use OPTN -> Edit (F1) while the value is highlighted to see a more precise value.

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Andy @andypmaths.bsky.social · 27/02/2025

OCR people have to use this. I do not like it because I can't draw a man in a cave and say the curve is concave.

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Andy @andypmaths.bsky.social · 23/02/2025

I'd say it's about as useful as this:

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Andy @andypmaths.bsky.social · 14/02/2025

I'm a big fan of 'blobs' for things like this (and various other topics, like chain rule).

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Andy @andypmaths.bsky.social · 26/01/2025

As others have said, it seems to be a hangover from when tables were used. Edexcel thankfully seem to have given up on using Z unnecessarily now in mark schemes. In the images here you can see they were clinging onto it in 2018 (1st MS), but by 2021 they'd finally let go (2nd MS).

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Andy @andypmaths.bsky.social · 17/01/2025

Your examples here are analogous to claiming that all computer graphics aren't very good and then using an Amiga 500 to justify your claim. I just ran both these queries through gpt 01 and it gave flawless answers.

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Andy @andypmaths.bsky.social · 14/01/2025

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Andy @andypmaths.bsky.social · 12/12/2024

It's also bizarre that they use f and g when hardly anyone teaches it that way. It's not like they couldn't use u and v because OCR do in their formula book.

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