monospace font recommendation

for the record, some new "coding ligatures" fonts that have decent international support:

Iosevka
typeof.net/Iosevka/

(from parent Source Code Pro)

Mensch
robey.lag.net/2010/06/21/mensc
(from parent Menlo)

Victor Mono
rubjo.github.io/victor-mono/

found via programmingfonts.org/

I like the _idea_ of Victor Mono but I think Iosevka looks better…none of them are as cute as Fira :(

Solving one problem at a time:

Are you interested in a federated alternative to Goodreads that doesn't use Amazon?

because I'm making a federated alternative to Goodreads that doesn't use Amazon

github.com/mouse-reeve/fedirea

Information on creating marbled paper with LaTeX! people.csail.mit.edu/jaffer/Ma.

You can find the package documentation here: ctan.org/pkg/pst-marble .

Sir Thomas Urquhart was a 17th-century Scottish eccentric who tried to systematize a new language for trigonometry; the law of sines was abbreviated as “eproso”, which (if you know the system) encapsulates its meaning.

blog.plover.com/book/Urquhart-

OMFG A FEDERATED SCHOLARLY COMMUNICATIONS PLATFORM!

I literally cannot wait to dig into this!! It's what I've been wanting!

olki.loria.fr/platform/

#Accessibility
A color contrast checker that offers alternatives if your color combination has not enough contrast. It would be cool to chose if you want to change background or foreground though but it's still very nice to get suggestions

polypane.app/color-contrast/#f

Challenge for applied category theory: build a ronavirus, so that the world can be sane again.

#DataVisualization can help us make sense of and teach about the coronavirus, but the stakes are high. @abmakulec@twitter.com has 10 considerations to help you #VizResponsibly:

medium.com/nightingale/ten-con

Who called it a magma and not a hemidemisemigroup?

ah yes, the classic proof

Mathemagics
Article by Pierre Cartier
In collections: Notation and conventions, The act of doing maths
My thesis is:there is another way of doing mathematics, equally successful, and the two methods should supplement each other and not fight.
URL: ftp.gwdg.de/pub/misc/EMIS/jour

I've just noticed that if you choose "wheelchair accessible" on google maps directions, it still shows an icon of a dude walking

The innovation here seems to be in the emphasis placed on the properties of the sum of the roots and the product of the roots.

And now, substituting into the formula for $$r$$ and $$s$$, we get $$r, s = -\frac{b}{2} \pm \sqrt{\frac{b^2}{4} - c}$$.

But this is just the same as $$\frac{-b \pm \sqrt{b^2 - 4c}}{2}$$, which is exactly what we would expect from the standard formula, given that $$a=1$$! The general derivation, for $$a \neq 1$$, takes a few more steps, but is fairly straightforward.

Now, the only way we can have $$r+s = -b$$ is if $$r = -\frac{b}{2} + z$$ and $$s = -\frac{b}{2} - z$$, for some $$z$$.

Since $$rs = c$$, this means that $$c = \frac{b^2}{4} - z^2$$.

Rearranging, we get $$z = \pm \sqrt{\frac{b^2}{4} - c}$$.

The trick is as follows: Assume, first of all, that $$a=1$$, and let $$r$$ and $$s$$ be the (unknown) roots. Then we can write $$x^2 + bx + c = (x - r)(x - s)$$.

Expanding the right-hand side, we get $$x^2 + bx + c = x^2 - (r+s)x + rs$$.

So we have $$r + s = -b$$, and $$rs = c$$.

Maths educator Po-Shen Loh has discovered a way to solve quadratic equations that is much more intuitive than $$\frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$, and is apparently unprecedented in the entire 4000-year history of thought on quadratic equations! See arxiv.org/abs/1910.06709.

I've just discovered something incredible: Jim Fowler has compiled TikZ to WebAssembly! That means you can render TikZ diagrams in web pages, **on the fly**!!
I've made a demo page with an editor, so you can see it and believe it: tikzjax-demo.glitch.me