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}
\begin{equation}
\mathcal{Re}\left{\frac{1}{2\pi} \int_{0}{\inf} 2F(\omega) \operatorname{e}^{i\omega t} d\omega \right}
\end{equation}
\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 āeā; probably you meant\mathrm, but this should be\operatorname{Re}. Also infinity is\infty, not\inf. ā egreg Feb 08 '17 at 09:47