# Equation and math system on same line

To add a math system into a LaTeX document, I add to preambol

\newenvironment{sistema}%
{\left\lbrace\begin{array}{@{}l@{}}}%
{\end{array}\right.}


then in the document I do something like

$\begin{sistema} cos(\beta x) \\ sen(\beta x) \end{sistema}$


But this time I need to write on a same line

f(x)=e^{\alpha x}P(x) + the math system of upper piece of code


What can I do?

Just combine them. Also use \cos and \sin to set the trig functions as functions, not variables.

\documentclass{article}
\newenvironment{sistema}%
{\left\lbrace\begin{array}{@{}l@{}}}%
{\end{array}\right.}
\begin{document}
$f(x)=e^{\alpha x}P(x) + \begin{sistema} \cos(\beta x) \\ \sin(\beta x) \end{sistema}$
\end{document}


• since the question is tagged [amsmath], the cases environment already exists. – barbara beeton Apr 15 '15 at 16:01

Another way to present the desired effect:

\documentclass{article}
\usepackage{amsmath}

\begin{document}
\begin{align}
f(x) = e^{alpha x} P(x) + \begin{cases} \cos(\beta x) \\ \sin(\beta x) \end{cases}
\end{align}

\end{document}


which yields