# MathJax Usage Guidelines

It's cool that we can use MathJax to do nice stuff like:

$$\{0+ai,0-ai^\frac{2}3,0+\frac{i}a,0-\frac{i}a\}\forall a \in A \subseteq \Bbb{R}$$

(stolen from this Jonathan Allan answer)

or this:

$$\sum_{i=0}^n i^2 = \frac{(n^2+n)(2n+1)}{6}$$

(stolen from this Mathematics Meta answer).

But we also have MathJax being used in cases like this question or this question or this question or this question, where's it's simply rendering digits differently. Or this answer where it does indeed help the formatting a bit, but is nothing that couldn't be achieved/communicated with regular characters.

# Why this might matter

So who cares? Just use it or don't, as long as the question is clear. Point taken, imaginary reader, but there might be a few downsides to using MathJax if it's not strictly necessary.

• Based on this answer, any question with MathJax in the title will be automatically excluded from the Hot Network Questions.

• It can, at times, make search results look weird:

• Based on this answer, MathJax is likely to eliminate a question/answer from being used on the Tour page. Yes that is a very tiny problem.

• Also doesn't seem like it works in "tooltips" on question hovering:

• As Alconja pointed out in comments, doesn't work in comments on mobile.

# So...

• Does this matter at all?
• Should we discourage and/or edit out uses of MathJax when they're not really necessary?
• Are there are general guidelines for when it is or isn't worth it to use MathJax? E.g., $$x^2$$ seems obviously better than x^2, but is $$4-3=1$$ that much better than 4 - 3 = 1?
• I don't have time to write a full fledged response but basically: Using or not using MathJax doesn't detract from the quality of puzzles being posted, and as I understand, that's the goal of this site. If there is an inconvenience with search results, in puzzles where MathJax isn't needed, one could simply notify the author with a comment. As to your last question: "Worth" is subjective and really only pertains to the author of the puzzle, if they feel like using MathJax and they think it's worth it, let them. – Areeb Oct 27 '16 at 22:07
• @Areeb I think this is a very valid question because it's not just the author of the question that might feel like using it. Anyone with edit rights may feel that the question (or answer) would look better with MathJax. Some guidelines may be helpful. – Gordon K Oct 27 '16 at 22:42
• @GordonK I feel that as long as both parties are ok with the edit, it's not really a problem. And if the author doesn't like the changes, they can always roll back, which is enough to get their message across. I don't see how guidelines would make too much of an impact, if any. – Areeb Oct 27 '16 at 22:47
• One other minor, but related point: mathjax in comments doesn't render in the mobile app (though it does in question/answer bodies) – Alconja Oct 28 '16 at 1:11
• I looooove to use MathJax, but avoid it when possible for just the reasons here and some others (e.g, render delay and font consistency). Much mathematics can be done without it, by using italics and <sup>/<sub> for instance. And then there's &frasl; for very nice simple fractions. – humn Oct 28 '16 at 4:05
• @Alconja I recently discovered that you can render MathJax in comments on mobile. You just need to tap on the comment, then tap the ... More button below it, and select Render MathJax from the list of choices. – GentlePurpleRain Oct 30 '16 at 2:49
• @GentlePurpleRain - Thanks for the tip. $\text{You learn something new every day}$... – Alconja Oct 30 '16 at 3:27
• What I don't like about MathJax is that it doesn't render in spoilers in mobile browsers (unless you open the spoiler before it loads). Search issues seem really minor, it's not like math expressions would look much better in plaintext. – ffao Oct 30 '16 at 14:31
• I use desktop version on mobile. It completely destroys mathjax. – user17008 Nov 1 '16 at 23:42