Ellipsis

Simply typing three periods in a row will not give the correct spacing of the periods if it is an ellipsis that is desired. So LATEX provides the commands \ldots and \cdots. Centered ellipsis should be used between symbols like +, -, *, ×, and =. Here are some examples:

\begin{mathegs}
\verb@$a_1+ \cdots + a_n$@ & $a_1+ \cdots + a_n$\\
\verb@$x_1 \...
...n = 0$\\
\verb@$f(x_1,\ldots,x_n) = 0$@ & $f(x_1,\ldots,x_n) = 0$
\end{mathegs}