MathJax Cheatsheet

This is a cheat sheet on which code / markdown notation leads to which MathJax output.

MathJax is an open-source JavaScript display engine for LaTeX, MathML, and AsciiMath notation that works in all modern browsers.

MathJax in Obsidian.md

When using MathJax inside Obsidian.md the markdown code representing the MathJax formula needs start and end with the dollar sign, i.e.: $a_1..a_n$

In order to show fractions a little bit bigger and centered use two dollar signs, i.e.: $$a = \frac{\sqrt{b^2 + c^2}}{2}$$

Printing little bigger works too with $\displaystyle$ ahead of the fraction

Cheatsheet

Description	Example	LaTeX Code / Markdown
Fractions	$\frac{km}{h}$	\frac{km}{h}
Text with spaces	$\text{kilometers or miles}$	\text{kilometers or miles}
Superscript / Exponent	$a^2+b^2=c^2$	a^2 + b^2 = c^2
Subscript	$a_1..a_n$	a_1..a_n
Double Subscript	$r_{0_1}+r_{0_2}+...+r_{0_n}$	{r_{0_1}​​ + r_{0_2} ​+ ... + r_{0_n}
Overline one character	$\bar{a}$	\overline a
Overline multiple characters	$\overline{AB}$	\overline {AB}
Hat over one character	$\hat{a}$	\hat a
Hat over two characters	$\widehat{ab}$	\widehat {ab}
Sum of a set	$\sum _{i=1}^n{a}_i$	\sum_{i=1}^n a_i
Sum of a set (larger)	$\sum _{i=1}^n{a}_i$	\displaystyle \sum_{i=1}^n a_i
Matrix with Parentheses	$\left(\begin{array}{cc}0& 1\\ 1& 0\end{array}\right)$	\begin{pmatrix} 0 & 1 \\ 1 & 0 \end{pmatrix}
Matrix with Brackets	$\left[\begin{array}{cc}0& 1\\ 1& 0\end{array}\right]$	\begin{bmatrix} 0 & 1 \\ 1 & 0 \end{bmatrix}
Complex Matrix with Parentheses	$\left(\begin{array}{ccc}& Bob& Alice\\ Bob& 0& 1\\ Alice& 1& 0\end{array}\right)$	\begin{pmatrix} & ​Bob & Alice \\ Bob & 0 & 1 \\ Alice & 1 & 0  \end{pmatrix}

Sources

I found the following sources which helped me out:

• https://de.wikipedia.org/wiki/Liste_mathematischer_Symbole (German)
• https://en.wikipedia.org/wiki/Glossary_of_mathematical_symbols
• https://math.meta.stackexchange.com/questions/5020/mathjax-basic-tutorial-and-quick-reference
• https://easy-copy-mathjax.nakaken88.com/en/matrix/
• https://jojozhuang.github.io/tutorial/mathjax-cheat-sheet-for-mathematical-notation/
• https://bearnok.com/grva/en/knowledge/software/mathjax