Problem with Equation Reference

[beth87]

I tried to use the following commands

Code: Select all  •  Open in writeLaTeX

\begin{equation}\label{xx} 3+4=7 \end{equation}

Referring to the equation \eqref{xx}

or

Code: Select all  •  Open in writeLaTeX

\begin{equation}3+4=7 \label{xx}\end{equation}

Referring to the equation \eqref{xx}

but it did not work...
it worked just if instead of \eqref{xx} I wrote \ref{xx}. Why is it so? Should I use a particular package? N.B I am using Texniccenter and Mixtek as a compiler

[localghost]

"It doesn't work" is an error description that is as good as useless. What is the exact error message from the log? As a random shot I would guess that you forgot to load the amsmath package.


Thorsten