This post summarizes symbols used in complex number theory.

\documentclass[11pt]{article}
\usepackage{amsmath, amssymb}
\begin{document}
\begin{description}
\item[Set of complex numbers:]$\mathbb{C}$
\item[Notation 1:]$z=a+ib$
\item[Notation 2:]$i^2=-1$
\item[Real part denotation:]$\Re(z)$ and $\operatorname{Re}(z)$
\item[Imaginary part denotation:]$\Im(z)$ and $\operatorname{Im}(z)$
\end{description}
\end{document}

**The set of complex numbers**

\usepackage{amssymb}
$\mathbb{C}$

See here for a complete list of set symbols.

**Complex number notation**

$a+bi$
$i^2=-1$

Nothing unexpected here, the standard *i* or sometimes *j* is used.

**Real part**

\usepackage{amsmath}
$\Re(z)$ and $\operatorname{Re}(z)$

**Imaginary part**

\usepackage{amsmath}
$\Im(z)$ and $\operatorname{Im}(z)$

### Like this:

Like Loading...

*Related*

Joel C. Salomon

This comes from Mathematica (IIRC) and is not otherwise standardized, but there may be some disambiguation benefit in using the double-struck italic letters from Unicode’s Letterlike Symbols block: U+2148 ⅈ and U+2149 ⅉ.

At the very least, I’ve found it useful to use those characters in my source code (via \newunicodechar) in case house standards require upright roman, or bold, or whatever formatting.

tom

Thanks for mentioning! Tom.

falowo

Hi

I want to put a curl over voltage symbol to signify that it is complex voltage . Do you know how to do it

tom

Hello,

I’m not familiar with the notation, which is why I might have gotten the symbols wrong. You might still find the code below useful.

Cheers, Tom.

Frovis

Hello i would like to put stripe over x like in this link http://www.gymnazium.milevsko.cz/dokumenty/sfm/pol_3/prumer.png . do you think you could help me pls ?

tom

Hi Frovis,

Here’s how to get ‘x-bar’ as shown in the picture:

Best, Tom

Teun Zijp

I hoped that

`\mathbb{i}`

would print the double-struck italic letters from Unicode’s Letterlike Symbols block: U+2148 ⅈ, but it prints a strange thing that is not even near my expectation… Could someone please fix this?tom

The stix package has a double-struck italics i, although I’m not sure this is the font you were looking for.