Math and Formulas

Pages do not typeset math. LaTeX written between math delimiters, such as $x^2$ or $$E = mc^2$$, is shown as ordinary text, not as a formatted formula. This page shows what happens to each kind of math you might type, and how to write a formula that reads well today.

What happens to LaTeX math

• Inline, with single dollar signs: $x^2 + y^2 = z^2$ is shown exactly as typed.
• Display, with double dollar signs: $$E = mc^2$$ is shown exactly as typed. Over several lines, each line stays a separate line of text.
• Inline, with backslash and parentheses: \(x^2\) shows as (x^2); the backslashes disappear.
• Display, with backslash and square brackets: \[x^2\] shows as [x^2]; the backslashes disappear.

Other things to know:

• Markdown still applies inside the dollar signs. $a*b*c$ shows the b in italics, $[a,b]$ turns a,b into a link to a page of that name, and \\ starts a new line.
• Backslashes before punctuation disappear. \{, \, and \$ show as {, , and $. Backslashes before letters, such as \frac or \int, are kept.
• Nothing is checked. A formula with a mistake in it looks the same as a correct one; there is no error message.
• Environments and extensions don't work. \begin{align}, matrices and chemistry notation such as \ce{H2O} are shown as text.

Dollar amounts

Dollar signs in ordinary text are always shown as typed. It cost $5 and $10. shows exactly that. You don't need to escape them, though \$5 also shows $5.

Writing a formula that reads well

• Short formulas: use superscript and subscript. E = mc^2^ shows E = mc², and H~2~O shows H₂O. Write no spaces between the marks.
• Symbols: type the character itself: x² ≤ π · r², α, ∑, √, ≠, ∞.
• LaTeX you want readers to copy: put it in a code span, `\frac{a}{b}`, or in a code block. Inside code, everything is shown exactly as typed, so nothing disappears and nothing turns into a link or italics:

```latex
\int_0^1 x^2 \, dx = \frac{1}{3}
```

• Larger or complex formulas: make an image of the formula and attach it to the page.

More help

• Markdown as we use it: everything you can write on a page
• Markdown Cheat Sheet: quick examples of each element