How to write A Plus-Minus Symbol in LaTeX

This article aims to show you the simplest and easiest way to create a plus-minus symbol in LaTeX.

LaTeX allows you to write documents that include equations, symbols, tables, and more. And sometimes, if you are tabulating data from an experiment, you will need the plus/minus sign or symbol.

With LaTeX you can include the plus-minus in your document, we are going to look at how to insert it in LaTeX.

Table of Contents

Plus-Minus Symbol

Most of the time in mathematics and science, the plus together with the minus, also known as the plus/minus symbol, is used and can have multiple meanings.

In mathematics you use the plus minus symbol, if you have the algebraic solution of a second order polynomial, or a square root solution. This is the most common appearance of the symbol.

Meanwhile in physics, you may need the plus minus symbol for measurement if you are tabulating values or a quantity with uncertainty errors. For example

Syntax

The plus-minus is generated using a command, no extra package or argument is required, it is a built-in LaTeX command. The command is \pm or \mp ,for example

\begin{document}
    $$ x = \pm 2 $$
    $$ x = \mp 2 $$
\end{document}

LaTex Plus/Minus

The plus-minus symbol must not be confused with the minus plus, they are different. The \pm command generates plus over minus.

Minus/Plus

The LaTex minus plus sign is the opposite, minus overplus. This occurs if you are simplifying an equation, and the plus-minus goes to the other side of the equation. It is generated with \mp command. Another example

\begin{align}
    x^2 \pm y &=0 \\
    x^2 &= \mp y
\end{align}

The aligned environment in the document is possible with the package amsmath.

Symbol minus plus, minus sign is above the plus

Math mode vs Text mode

Now, you usually work in math mode, denoted by $, $$, or \[ \] when you need to use a command for a properties value symbol, thus we cannot use the \pm command or \mp command outside math mode.

Therefore you always have to open the math mode within the text mode to use it, using a $ to open and a $ to close. For example

%minus plus sign/symbol\[
  x^2+bx+c=0 \implies x=\frac{-b \mp \sqrt{b^2-4c}}{2}
\]
%plus minus sign
$$
  x^2+bx+c=0 \implies x=\frac{-b \pm \sqrt{b^2-4c}}{2}
$$% quadratic formula in a LaTeX document
In Text mode we open Math mode to use the $\pm$, $\mp$ symbol.

Wherever you write the command in the LaTeX document, the symbol will be there. Remember it does not require an argument.

There are exceptions to using it in text mode but they require external packages, and sometimes it is better to use already built-in LaTeX commands.

You now know how to insert this useful symbol in LaTeX. Surely this tutorial was helpful in guiding you in LaTeX.