Need help with two symbols for Complex Analysis

Question

I cannot find how to write "cis" which is the polar form of complex number, or "Arg" which is short for argument. Does anybody know these symbols? Thanks.

If these are symbols, we need to see what they look like. Of course, it would help if you could review the approaches listed in How to look up a symbol or identify a math symbol or character? — Werner, Jan 14 '15 at 18:55
cis should look similar to the symbol cos for cosine, or sin for sine. Arg should just look like Arg. The point is that they are functions and need to have input with them. — nonremovable, Jan 14 '15 at 19:00
You can define your own operators, if not already defined. I forget the syntax, but at the package level, \def\Arg{\mathop{\operator@font Arg}\nolimits}, which is how \sin is defined, substituting Arg in its place. If defining it in your document, surround by \makeatletter and \makeatother. — Steven B. Segletes, Jan 14 '15 at 19:00

score 11 · Accepted Answer · answered Jan 14 '15 at 19:07

11

Put this in your preamble:

\usepackage{amsmath}
\DeclareMathOperator\cis{cis}
\DeclareMathOperator\Arg{Arg}

answered Jan 14 '15 at 19:07

Bernard

271,350

score 2 · Answer 2 · answered Jan 14 '15 at 19:06

\documentclass{article}
\usepackage[T1]{fontenc}
\makeatletter
\def\Arg{\mathop{\operator@font Arg}\nolimits}
\def\cis{\mathop{\operator@font cis}\nolimits}
\makeatother
\begin{document}
sin is defined as\\
\meaning\sin

$\Arg x \ne \cis y$
\end{document}

enter image description here

The fontenc package is not needed for the operator definition, but only to properly show the meaning of \sin.

Need help with two symbols for Complex Analysis

2 Answers2