Some new users don't know and not familiar with the $\LaTeX$ syntax. It is perfectly normal but it would be better if we refer them a nice reference that explains the basics.
Also, I suggest that we can add a link to this question in the help page.
The math mode can be used for inline in $...$
as $x^2+x$ and for centered new line $$....$$
as; $$x^2+x$$
MathJax supports essentially the commands native to $\LaTeX$ as well as those defined by amsmath
and amssymb
(with some exceptions in both directions). For a complete list, see the MathJax reference.
Here some helpful one;
x_2
$x_2$, if more than one char use braces x_{12}
$x_{12}$x^2
$x^2$, if more than one char use braces x^{12}
$x^{12}$\operatorname{name}
for names of the operators with non-italic and spacesing\mathbb{Z}
for groups, fields as \mathbb{Z_p}
$\mathbb{Z_p}$, $\mathbb{F_q}$\mathcal{O}
for calliographic letters, \mathcal{O}
, $\mathcal{O}(n \log n)$ align
to align the equations; as \begin{align*} A & = B \\ & = C \end{align*}
aligned with =
$$$$ \begin{align*} A & = B \\ & = C \end{align*} $$$$ \dots
for ...
Mathjax Latex Commands
$\endgroup$