Symbol/Unicode | Sigma/U+03A3 |
---|---|
Type of symbol | Mathematics |
Package (requirement) | No |
Argument | No |
Latex command | \Sigma |
Example | \Sigma → Σ |
A letter of the Greek alphabet is sigma, in mathematics, it is used as a summation operator.
In latex, you have to use \Sigma
command for the small size of sigma and \sum
for big size of sigma.
\documentclass{article}
\begin{document}
$$ \Sigma $$
$$ \sum $$
\end{document}
Output :
Sigma symbol with limits
You can use the \Sigma_{subscript}^{superscript}
command to use limits with the sigma symbol. But it is not a good practice.
\documentclass{article}
\begin{document}
$$ \Sigma_{i=1}^{100} i $$
$$ \Sigma_{i=1}^n =kn $$
$$ \Sigma_{i=1}^\infty $$
\end{document}
Output :
In the example above you can see that the best result is not coming in the case of using limits or it does not look so professional.
So in this case you can use the \sum
command and use the \sum_{subscript}^{superscript}
command to use the limits with the symbol.
\documentclass{article}
\begin{document}
$$ \sum_{i=1}^{100} i $$
$$ \sum_{i=1}^n =kn $$
$$ \sum_{i=1}^\infty $$
\end{document}
Output :
Create command for sigma with limits
You can create a custom latex command using the \newcommand{}[]{}
command to simplify the process.
You can also use the \limits
command, no problem if you don’t use it but it is a good practice to use it to set limits. Below are some examples.
\documentclass{article}
\newcommand{\summation}[2]{\sum\limits^{#1}_{#2}}
\begin{document}
$$ \sqrt{\frac{1}{N}\summation{N}{i=1}(x_i -\mu)} $$
$$ \summation{n}{i=1} i=\frac{n(n+1)}{2} $$
\end{document}
Output :