latex

# How to Create and use summation symbol in LaTeX

In mathematics, summation refers to adding a series of any type of digits. We can easily perform summation on other forms of values along with the new numbers. In mathematics, we express summation with the sigma symbol, “∑,” which is a Greek capital letter.

An index accompanies this symbol that encompasses all the essential terms to be considered in the sum. Hence, the summation symbol has a vital role in mathematical expressions. So, let’s look at the methods for creating and using summation in LaTeX.

## How to Create and Use a Summation Symbol in LaTeX?

To write a summation symbol in LaTeX, you can use codes like \sum, \sigma, etc. Let’s start with the simple examples and use these source codes to write the summation symbols:

\documentclass{article}

\begin{document}

Either you can use:

$$\Sigma x_i$$

Or else:

$$\sum x_i$$

\end{document}

Output

Similarly, you can create different types of mathematical equations using the following source codes:

\documentclass{article}

\begin{document}

$$\Sigma A_x$$ \\

$$\Sigma \frac{4}{(A_x)+(B_x)}$$ \\

$$\Sigma_{x=1}^M (A_x)$$ \\

$$\sum A_X$$ \\

$$\sum \frac{4}{(A_x)+(B_x)}$$ \\

$$\sum_{x=1}^M (A_x)$$ \\

\end{document}

Output

Let’s take another example that contains a summation symbol with the above or below limit condition:

\documentclass{article}

\usepackage{amsmath}

\begin{document}

$\sum_{i=2}^{M}A_i = A_4 + A_3 + A_2 + A_1+ \cdots + A_M$

\end{document}

Output

You can add multiple expressions under the summation using the \atop source code:

\documentclass{article}

\begin{document}

$\sum_{ 1 \leq x \leq A \atop 1 \leq y \leq A }B_{x,y}$

\end{document}

Output

Now let’s write the source code to use multiple summation symbols in the mathematical expression:

\documentclass{article}

\begin{document}

$$\sum\limits_{X=1}^A\sum\limits_{Y=4}^B C_X D_Y$$

$$\sum\limits_{X=1}^\infty\sum\limits_{Y=4}^\infty \frac{5}{A^{X+Y}}= P$$

$$\mathit{if}|\mathit{B}|>1$$

\end{document}

Output

## Conclusion:

This was the concept of summation and the methods for writing and using the summation symbol in LaTeX. We have included two different codes and examples to explain everything easily.