# Equation numbered two times

Using the align function, I get that my equation placed on two lines is numbered two times.

\documentclass{beamer}
\usetheme{malmoe}
\begin{document}
\begin{frame}{Test}
\begin{align}
E_{t-1}[r_{i,t}] = &\,\phi_{i,t-1}\,\lambda_{t-1}\,cov_{t-1}[r_{i,t},r_{w,t}]\,+\\
&(1 - \phi_{i,t-1})\,\lambda_{i,t-1}\,var_{t-1}[r_{i,t}]
\end{align}
\end{frame}
\end{document}


• Well, you're splitting the equation ... each line is numbered, unless you use \nonumber\\ for the first one or \nonumber for the second one, depending on which line should be numbered – user31729 Mar 7 '17 at 15:32
• Would you like the numbering to be on the first line, second line, or in between the first and second line? – Troy Mar 7 '17 at 15:32
• Thanks all for you prompt reply. @Troy, Denis's code works well for between lines. What if I want to the numbering to be on the second line? (just for the purpose of learning) – Alan Mar 7 '17 at 15:45
• @Alan You can use Christian's method. Use \nonumber or \notag before you skip the line with \\ . It basically tells LaTeX that you don't want the first line to be numbered. – Troy Mar 7 '17 at 15:56

Try

\documentclass{beamer}
\usetheme{malmoe}
\begin{document}
\begin{frame}{Test}
$$\begin{split} E_{t-1}[r_{i,t}] = &\,\phi_{i,t-1}\,\lambda_{t-1}\,cov_{t-1}[r_{i,t},r_{w,t}]\,+\\ &(1 - \phi_{i,t-1})\,\lambda_{i,t-1}\,var_{t-1}[r_{i,t}] \end{split}$$
\end{frame}
\end{document}