Try out KaTeX with sans-serif font

[Entkenntnis]

Students are sometimes confused by serif font, especially the x.

We could try to default all math formulas to sans-serif and see it this brings an improvement.

[elbotho]

okay, I researched this a bit.
completely switching fonts won't really work with KaTeX.

But KaTeX comes with a sans-serif font that can be activated using using \sf, \mathsf{example} or \textsf{example}. All should result in the same output.

The result… is not great. If it uses sans-serif fonts it's okay, but looks a bit out of place. And then it still uses serifs for some parts. It even displays the same symbols differently sometimes, which is super confusing.

Examples

• completely works here
• hmm…
• well…

Pings
@Entkenntnis feel free to play around.
@kathongi take a look!

[kathongi]

I don't understand the problem to be honest. I think it looks quite good with the new font. Not worse than the standard LaTeX font.
I also asked some authors from the academy and got positive feedback. They said it looks more modern and less threatening :D

[elbotho]

@kathongi
Mostly things like this put me off, where same variables (a,b) are displayed in two different ways.
You can definitely judge this betten than me … isn't this confusing for learners?

(left vs right)

[Entkenntnis]

@elbotho After some investigation all cases of serif fonts are content problems: Your example on the left is using serif fonts explicitly in the latex code (huch?), and the on the page with logarithms, some formulas are not correctly inserted (not using math environment), somehow causing the frontend converter to ignore them (only happen in legacy content).

@kathongi Thank you for the feedback, I do agree that it looks more modern and more like school book style.

So in summary, I would merge the PR into staging.

[elbotho]

@Entkenntnis nice, thanks for investigating 👍
It was super easy to find those examples, how should we handle those cases?

(In general im not against merging this :)

Forced serifs: What code is used to archive that, could we re replace to automatically get rid of it in the meantime?

[Entkenntnis]

@elbotho As long as an article is not converted (see https://are-we-edtr-io-yet.serlo.org/), we can assume that project convo will work through these cases.

Otherwise, if we encouter such code in converted content, I would probably talk with the authors. Its mostly not necessary to write such code