# Troubles with implementing a Fourier-transform formula [duplicate]

I am trying to write a formula, which includes operators Re{}, F(\omega) and e(). Anyways, it doesn't work, I know I must be missing some parantheses, but I can't figure out where or what else might be wrong:

\documentclass[11pt,a4paper, oneside]{article}
\usepackage[utf8]{inputenc}
\usepackage[ngerman,english]{babel}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage[free-standing-units]{siunitx}

\begin{document}

$$\mathcal{Re}\left{\frac{1}{2\pi} \int_{0}{\inf} 2F(\omega) \operatorname{e}^{i\omega t} d\omega \right}$$

\end{document}

• \left{ should be \left\{ (similarly for \right). If you want an upright font for the Euler number, use \mathrm{e}, not \operatorname{e}, which is wrong. By the way, \mathcal{Re} prints a funny symbol instead of an “e”; probably you meant \mathrm, but this should be \operatorname{Re}. Also infinity is \infty, not \inf. – egreg Feb 8 '17 at 9:47

Some suggestions:

• You meant to write \infty rather than \inf, right? Don't forget typing ^ to place \infty in the upper limit of integration.

• Write \mathrm{e} for Euler's number.

• To generate curly braces, you need to write \{ and \}, respectively.

• \mathcal is only implemented, at least in the amssymb package, for uppercase letters.

• It's somewhat customary, though by no means required, to insert a thinspace between the integrand and the variable of integration.

\documentclass[11pt,a4paper]{article}
\usepackage{amssymb}
\begin{document}

$$\mathcal{R}\left\{\frac{1}{2\pi} \int_{0}^{\infty} \! 2F(\omega) \mathrm{e}^{i\omega t}\, d\omega \right\}$$

\end{document}