You will see very few symbols which are used a lot. But, one of them is the tilde symbol. In this tutorial, each use of the tilde symbol is represented with the help of LaTeX.
The tilde symbol is sometimes used above the letter, sometimes below the letter, and sometimes along with the letter. So, there are different commands and packages for this.
Tilde symbol above the letter
This tilde symbol is used on some special characters in Spanish and Portuguese. To use the tilde symbol on a character using latex, you need to use the \~{} and \tilde{} commands.
\documentclass{article}
\begin{document}
\~{a} \; \~{n} \; \~{o}
\end{document}Output :
ã ñ õ
But, you have to use \tilde{} command in math mood, you can’t use it in direct text.
\documentclass{article}
\begin{document}
\[ \tilde{a} \]
\[ \tilde{n} \]
\[ \tilde{o} \]
\end{document}Output :
ã ñ õ
In Spanish, this symbol is used only above the letter n.
\documentclass{article}
\begin{document}
ni\~{n}o = child \\
ara$\tilde{n}$a = spider
\end{document}Output :
niño = child araña = spider
In the case of Portuguese, the tilde symbol is used on the vowels a and o.
\documentclass{article}
\begin{document}
sal$\tilde{o}$es = saloons \\
coraç\~{a}o = heart
\end{document}Output:
salões = saloons coração = heart
It is best practice to use the latex \~{} command for Spanish and Portuguese languages.
Tilde symbol below the letter
You will see very few cases where the tilde symbol has been used below the letter. In this case, we will take the help of tipa and accents packages. The tipa package contains the \textsubtilde command.
\documentclass{article}
\usepackage{tipa}
\begin{document}
\textsubtilde{a} \\[6pt]
\textsubtilde{e} \\[6pt]
\textsubtilde{o} \\[6pt]
\textsubtilde{A} \\[6pt]
\end{document}Output:
However, two arguments must be passed to the \underaccent command. The first is \tilde command and second is letter.
\documentclass{article}
\usepackage{accents}
\begin{document}
\[ \underaccent{\tilde}{a} \]
\[ \underaccent{\tilde}{e} \]
\[ \underaccent{\tilde}{o} \]
\[ \underaccent{\tilde}{n} \]
\end{document}Output:
Tilde symbol in mathematics
There are different parts of mathematics. Although the symbol is the same, the meaning of the symbol is not the same everywhere.
1. In Algebra, a single tilde or double tilde symbol is used for approximately or approximately equal.
\documentclass{article}
\usepackage{amssymb}
\begin{document}
\[ \pi \sim 3.14 \]
\[ a \approx b \]
% amssymb package for \thicksim and \thickapprox commands
\[ \pi \thicksim 3.14 \]
\[ a \thickapprox b \]
\end{document}Output:
π ∼ 3.14 a ≈ b π ∼ 3.14 a ≈ b
Also, a single tilde symbol is used to subtract between two numbers in the specific case.
\documentclass{article}
\begin{document}
\[ 9 \sim 7 \]
\[ 10 \sim 5 \]
\end{document}Output:
9 ∼ 7 = 2 10 ∼ 5 = 5
2. In set theory, when two sets are equivalent, the equivalence of the set is denoted by a single tilde notation.
\documentclass{article}
\begin{document}
\[ A \sim B \]
\end{document}Output:
A ∼ B
3. In geometry, the approximate symbol is used on an equal symbol when two triangles are equal. For example
\documentclass{article}
\begin{document}
\[ ABC \sim PQR \]
% \cong command for ≅ symbol
\[ ABC \cong PQR \]
\end{document}Output:
ABC ∼ PQR ABC ≅ PQR
Tilde symbol in computer commands and programming language
1. In language, the bitwise complement operator and general sibling selector are denoted by tilde notation. For example
\documentclass{article}
\begin{document}
\[ x = \; \sim 2 \]
% for css general sibling selector
\[ div \sim p \]
\[ div \sim h2 \]
\end{document}Output:
x = ∼ 2 div ∼ p div ∼ h1
2. In commands, if you are using a Linux operating system, you will notice that this notation indicates the home directory.
\documentclass{article}
\begin{document}
\[ cd \sim \]
\end{document}Output :
cd ∼
