# Correctly Format Text in Equations

When writing a mathematical equation that contains a word or other string of characters that is a unified block, place those characters inside a `\text{...}`

macro.

To understand why this is important, suppose you have defined \(a,\) \(n,\) and \(t\) as real numbers.
What does the expression \(tan(a)\) mean? Anybody experienced with trigonometry, would read this as the tangent of \(a,\) but because juxtaposition indicates multiplication, the expression is ambiguous—it could also be read as \(t\) times \(a\) times \(n\) times \(a.\)
To avoid this ambiguity, write \(\tan(a)\) (`$\tan(a)$`

or `$\operatorname{tan}(a)$`

).

The particular way that you format a string depends on the context.

`\operatorname{}`

to define functions like $\sin$ and $\cos$ that consist of several characters. Based on the context,`\operatorname{}`

inserts the proper spacing before the text.`\text{}`

to insert plain text that matches the formatting of the surrounding text environment, such as`\text{if } ...`

`\text{otherwise} ...`

in a`cases`

environment.`\textup{}`

to insert upright text. Useful for equations that appear in italicized environments, like theorems.`\texttt{}`

to format programming variables and other code-like text.`\textsc{}`

to format text using “small caps”.

If the string of characters appears repeatedly, define a macro to make it easier to typeset.