Align equations not displaying?

1. Oct 25, 2008

tgt

The \begin{align} \end{align} is not displaying anything. What have I done wrong?

2. Oct 25, 2008

cristo

Staff Emeritus
Erm.. not put anything between the two commands?...

Seriously, it's very difficult to troubleshoot something if you don't give any information about your problem! Have you got the amsmath package installed?