it looks like it's just ignoring large parts of my query. "derivative of {x,x^2}" produces the same result: wolframalpha.com/input/?i=deri+
I still can't see how you get from {x,x^2} to x^3+x^2.

I can't work out what WolframAlpha is doing wrong with this query: wolframalpha.com/input/?i=deri"derivative of (vector{1,2} dot vector{x,x^2}) with respect to x"

It can do the dot product properly on its own: wolframalpha.com/input/?i=vect

john venn: ok now fellas, i know you all hate me for my obsession with making diagrams, and also for my obsession with set theory, but which of you hate me for both? observe,

The phishing is coming from _inside_ the social network!

This from the "bet you can't kick yourself in the nuts" school of psychology

God may not play dice with the universe, but something strange is going on with the prime numbers -- Paul Erdös (1997)

Just learned about this handbook for making complex visual images such as charts, diagrams, mathematical graphs, and more. It's super helpful for anyone posting educational content online! Plus, it's #CC licensed. #a11y pcc.edu/instructional-support/

Trying to have a conversation with a colleague, but all I can think about is how comfy this new jumper is.

Food

Is my daughter too young for NP-hard problems?

mathstodon.xyz users: I've found out why LaTeX sometimes isn't rendered: it's a bug in MathJax! See github.com/mathjax/MathJax-src for the details.
For now, I think you can avoid it by not putting a math delimiter at the start of a line. Even a single space should be enough to avoid the bug.

> We have computed the very first chosen-prefix collision for SHA-1. In a nutshell, this means a complete and practical break of the SHA-1 hash function, with dangerous practical implications if you are still using this hash function. To put it in another way: all attacks that are practical on MD5 are now also practical on SHA-1. Check our paper here for more details.

When on eduroam do as the umm ... eduroamans do??

🧵

Food

@bremner Me, a Mathematica user for decades: Why yes, (#^%%)! & /@ %%% seems like a perfectly reasonable thing to write, why do you ask?

Ed Pegg, Jr has started updating mathpuzzle.com/ again! Hooray!

John Wallis and the Roof of the Sheldonian Theatre: soue.org.uk/souenews/issue4/wa, via an @aperiodical description of a 3d print of the same structure, aperiodical.com/2019/11/my-adv

It's an elegant way to build a wide roof out of short beams with no joinery. But the history is somewhat lacking: Similar structures were known much earlier to Leonardo Da Vinci, Villard de Honnecourt, and Sebastiano Serlio. See Sylvie Duvernoy, "An introduction to Leonardo's lattices", doi.org/10.1007/978-3-7643-872

Elf (Nirvana Systems/Ocean Software, 1992) #DOSGaming

@answer_smaths this is one of my favourite ones

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.