Pinned toot

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"?

massive solar flare shockwave...

I'm looking in A-Level 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!

smooth jazz, piecewise-linear jazz, topological jazz

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!

@christianp The space before the $dx$ in an integral (unless you’re picky and write $\text{d}x$).

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 mathworld.wolfram.com/Prosthap

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!

400. THE MAGIC STRIPS. I happened to have lying on my table a number of strips of cardboard,
with numbers printed on them from 1 upwards in numerical order. The idea suddenly came to me, as ideas have a way of unexpectedly coming, to make a little puzzle of this. I wonder whether many readers will arrive at the same solution that I did.

Take seven strips of cardboard and lay them together as above. Then write on each of them the numbers 1, 2, 3, 4, 5, 6, 7, as shown, so that (1/3)

me: i can't tell my date that i'm mid-1840s mathematician sir william rowan hamilton
-later, on a bridge-
date: hello there
me: BY GOD I'VE FIGURED IT OUT

Macaroni is plural. Disagree? The macaronus is on you to prove me wrong.

Talking of deals you should walk away from...

the category theorist bowed his head solemnly and spoke: "theres actually zero difference between good & bad things. they are equivalent up to isomorphism. obviously. intuitively"

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!

A Mastodon instance for maths people. The kind of people who make $\pi z^2 \times a$ jokes.
Use $ and $ for inline LaTeX, and $ and $ for display mode.