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For me, this is the best method to solve (better than completing squares, general quadratics formula, factorization, ...)

(Credits from "l hodge" - @l_d_hodge on twitter)

It's easy to understand, it works with $a \neq 1$ and it has meaning.

It's based on change of variables and

@codeberg is there any size limitation in repos at codeberg. Many repos hosting services put limits in the size of repos. Does codeberg also do?

Xavier B. boosted


Le développement de PDF4Teachers continue avec le système de notation par compétences !

✅ Cette fonctionnalité tant attendue pourra être utilisée en parallèle de la notation chiffrée, avec un support de l'importation et exportation vers SACoche.


Xavier B. boosted

Ah, new ways to fold a cube dropped

Or, Erik Demaine et al. present cube-folding puzzles and results — such as folding a cube from a 3x3 square on half-unit lines and diagonals (close to the non-grid minimum of \(2\sqrt{2} \times 2\sqrt{2}\), or from a 2x5 rectangle with a slit with folds on a unit grid!

The 2x5 grid-fold puzzle initially looked impossible to me, so I made a paper model — and it turns out not only is it possible, it's also reasonably stable! to 

@codeberg I will consider because in codeberg I can't see the tags in log like cgit does. I know it's a "missing feature" from gitea.

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I moved definively to @codeberg because is down constantly: xmas, february, june. The non-profit aspect of codeberg, open-source backend and free-service decided me. However I like very much the minimal interface.

I considered but $20 is too much for me.

@andrewrk As a user and ocasional programmer, I dream to have (python implementation in ). That would bring the simplicity of python implemented in very secure language like zig.

Opcions per allotjar continguts a la web 

Només hi ha tres opcions: o pagar (p.e. VPS) o allotjar-lo un mateix o no pagar res però consentir que el que et dóna el servei s'aprofiti de tu (publicitat, venda de dades, etc.).
En els dos primers casos tendreu feina d'administradors de sistemes, probablement, o no podreu treure profit a tot el potencial de la màquina (ex. només poder allotjar un blog, no poder servir determinats arxius, etc.)

Xavier B. boosted

Owen Lynch and I recently figured out how to unify traditional thermodynamics, classical statistical mechanics and quantum stat mech in a single framework based on entropy maximization. You can learn about it in his talk here!


Xavier B. boosted

I watched "The unreasonable effectiveness of complex numbers in discrete math" by 3blue1brown last night.

Which I found quite fun. It starts off with what seems like an intractable problem, and the proposed tooling to solve it seems very wtf. But as the it progresses, it makes sense and starts to appear almost intuitive. Using generating functions, complex roots of unity and their rotational symmetry. #Math

Is there some objective classification of objects in 3D? Something like organic chemistry names? I think most names in 3D are arbitrary: why we say cylinder intead of circular prism? Can we name figures in more armonic and consequent way? It would give our students more deep comprehension about tridimensional fig.

4/2 Opinion about non-(open-source) software in Maths 

The open source is the only way of assure what some program does.

Release something in open source license are good for the users (who have more liberties) and for the programmers (perhaps you have espontanious translators and contributors)

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3/2 Opinion about non-(open-source) software in Maths 

Indirect proof of that is that the latest post of his blog are about the technology not about activities:

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2/2 Opinion about non-(open-source) software in Maths 

It's really worrying that many places just want you to buy or use their products because somehow they earn money.

The mercantilization of everything, in particular math software, is disgusting.

Dan Meyer was a secondary teacher with some great ideas []. He has a great blog with many activities []. He left teaching and he became a software seller [Desmos calculator].

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1/2 Opinion about non-(open-source) software in Maths 

Desmos anounced that it has acquired by Amplify []. Really, Amplify just acquires one part: Desmos curricula and Desmos calculator remains independent.

Be aware of tools which are non free software, or at least open source, because you are dependent on some software and you could possible trapped there.

I never have been used desmos because I only use free software in my classrooms.

For me, this is the best method to solve (better than completing squares, general quadratics formula, factorization, ...)

(Credits from "l hodge" - @l_d_hodge on twitter)

It's easy to understand, it works with $a \neq 1$ and it has meaning.

It's based on change of variables and

Anyone knows a simple or elementary proof that $$n = \Delta_s + \Delta_k + \Delta_m$$ where $$\Delta_i = i(i+1)/2$$ the i-th number?

Conseqüències indesitjables de la COVID 

- Prefereix venir, perquè els mirin.
(després d'uns segons) És que fan una comedi amb el coronavirus....
- Bon dia
- Dónau-li les gràcies al metge.
- Adeu

Abans d'això les persones afectades varen esperar 10 minuts i el metge no els atenia fent papers.

Fins a on hem arribat! Que les persones que no tenen una malaltia no puguin ser ateses a la sanitat (pública). On és el jurament hipocràtic! On és la professionalitat

Que la COVID-19 no sigui una excus

Conseqüències indesitjables de la COVID 

- Sí és pell atòpica [li toca sa pell]. Vostè no ha de venir?
- Jo he cridat per telèfon i m'han dit que podia venir
- Qui li ha dit?
- No sé, una dona
El metge fa la recepta i torna a dir
- Vostè no ha de venir
- I com li enseny la costrera?
- Amb una foto
- Sí, amb una foto (amb to irònic)
- Sí, ho feim. La gent envia fotos
- I com toca les coses amb una foto (recordant que ha tocat la pell atòpica de la nina)?
- Ho feim per vostès perquè no s'exposin

Conseqüències indesitjables de la COVID 

1/2 Una conversa real entre un pacient i un metge a un PAC:
- Bon dia
- Bon dia
- Venc perquè al meu fill li ha sortit una costra al nas que li creix dia a dia
- Sí, això és un [...] Li ha de donar una pomada
- Sa nina també li ha sortit una crostera a l'esquena. Supòs que li ha passat. Li ho pot mirar?
- Clar que sí
- A part d'això, li han tornat a sortir uns granets a la panxa. El Dr. Verd ens va dir que basta que li posassin vasselina

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