Christian Lawson-Perfect @christianp@mathstodon.xyz

Hallo, new Mastodon users! Here on mathstodon.xyz we've got a couple of mathematical emoji: and . I'd love to add some more. If you can make a PNG image the same size as those, send it to me and I'll add it. Faces of famous mathematicians are an easy place to start; could we have some shapes, polyhedra, or other mathographics too?

This is more what I was looking for: in the C3 book, they ask you to simplify \(\sin(\theta) \cos (\theta) (\sec (\theta) + \operatorname{cosec}(\theta))\). The answer they give is \(\sin(\theta) + \cos(\theta)\).
So do they mean "put it in terms of sin and cos"?

I'm looking in A-Level #math textbooks for examples of "simplification".

On the first page of content in this EdExcel C1 book, this made me so cross: you're not applying the rule \((a^m)^n = a^{mn}\), you first need \((ab)^n = a^n b^n\), but that rule isn't even listed!

Prompted by @11011110, I've had a go at making a Mathstodon emojo:

It's a 𝕄 with an elephant's trunk. Helpful suggestions for my colourblind eyes welcome!

Whitespace is important in matrix notation: \( \begin{pmatrix} 1 & 2 \end{pmatrix} \) is not the same thing as \( \begin{pmatrix} 12 \end{pmatrix} \).

Are there any other instances of sensitivity to whitespace in mathematical notation?

I had never heard that the standard trigonometric addition formulae have a really long-winded name: the prosthaphaeresis formulas http://mathworld.wolfram.com/ProsthaphaeresisFormulas.html

We now have a Grace Hopper emojo, , for when the bugs are losing

we need a Grace Hopper emoji

I'm glad I'm taking the time to write unit tests for this code. So many bugs!

Talking of deals you should walk away from... #PeoplesVote

That's a nice magic square! https://mateturismo.wordpress.com/2018/10/15/el-cuadrado-magico-orlado-de-zurgena/

oh never mind, I forgot that the unit tests load a concatenated copy of the code that needs to be remade. 2 tests fail. Oh well!