Is it required to use MathJax for simple listings of numbers?

Question

I was curious. Normal Human recently told me that MathJax is the site's syntax. I am well aware of that and figure that it is just being automated. However, I'm curious whether you must use MathJax for representing simple things such as 1+x?

Answer 1

1+2+3+4+5+...+n is a mathematical formula presented as plain text. While it is readable as such, presenting it as $1+2+3+4+5+\cdots+n$ is a more semantic approach, which allows for the structure of the formula to be parsed and presented as mathematical markup (MathML).

I'm not the only one commenting on the formatting of your posts: you received a similar comment on this answer today. And in this recent answer you also presented formulas such as n(n-1)x^(n-2) as plain text. So yes, there is room for improvement.

Answer 2

In my opinion there's no need to use MathJax as long as one simply mentions a number in the middle of a prose paragraph -- the default text font has prefectly servicable digits that can be used for that.

However, once one progresses to mathematical expressions with symbols in them -- even just for arithmetic such as $+$ and the like -- then MathJax produces nicer text. And then freestanding numbers that are connected to those calculations should be in MathJax too, for consistency. This also goes for variable names. Variable letters ought to be set in italic, and even if the variable is never used in an actual formula, writing $x$ is not much more of a burden than writing _x_.

On the other hand, numbers that are not mentioned as objects of the mathematical discourse might as well be in the plain text font. So I would write, for example,

In 1975, John Doe published a proof that $\pi=4$. Doe acknowledged that most authorities hold that $4$ is too large a value, but argued that they were just jealous of his genius. He released a revised 34-page proof in 1979.

But in a different answer where I need no formulas, I wouldn't hesitate to write

I think my favorite prime is 61, but I also have weak spots for 11, 257, and 2147483647.

without MathJax.

Answer 3

For "simple listings of numbers" I would say no, it's not required. For example, to list the Fibonacci numbers: 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, ... I see this as a trade-off: by not invoking math mode for that listing, your browser displays it faster, but because the default font for regular text on this site is something like Georgia, it doesn't look quite as good as it would look in math mode.

But $1 + x$ is quite a different thing, it's not as simple a thing as a bunch of integers. In addition to a numeric literal, it also involves an arithmetic operator and a variable designated by a letter of the Latin alphabet. Unless you're a political columnist writing a political column, there is no excuse to use regular text for Latin alphabet variables.

It can put up unnecessary roadblocks to reading distinguishing between English words, abbreviations and expressions with tacit multiplication operators. In one of your recent answers, you write "fyi" presumably to mean "for your information." A Sheldonian might wonder if you meant $f \times y \times i$ or $f(y \times i)$ or even (quite implausibly, of course) $\int y \times i$.

Answer 4

I my point of view, it is good(may be necessory) to use mathjax whenever you are using mathematical expressions.

for example, when i wish to type like $$\text{Let} f \text{ be a function}$$ We must use mathjax for that $f$ also. Why because, if you are normally typing like 'f' this look like the normal text

                                      'f'. 

But if you are typing it inside the dollars like $f$ you will get the result as, $$f$$

Compare the difference,

And similarly,

For variables, numbers, and simple expression you can find the differences in the below table

$\begin{array}{cc} \text{without Mathjax} & \text{With Mathjax}\\ \text{x} & x\\ \text{z} & z\\ \text{1+2+3+...} & 1+2+3+\ldots\\ \text{...} & \ldots\\ \text{i.e.,} & i.e., \end{array}$