Math & Science ⇒ Page break within the array.

[cgnieder]

The second problem is I want to make newenvironment for this, so that I don't have to change whole document. But the "\align" is showing the equation number and "\align*" is not working.

You could use the environ package:

Code: Select all

\documentclass{article}

\usepackage{mathtools}
\usepackage{environ}

\NewEnviron{alg}{ \begin{align*}\BODY\end{align*} }

\begin{document}

\begin{alg}
 & \Rightarrow & \sin\theta &=\sin\frac{\phi}{2}
\end{alg}

\end{document}

[Pushpkant]

Thank's a lot Stephan and cgnieder.

But I have found more convenient way to write these equations without changing my whole document.

I just used IEEEeqnarray instead of array
the IEEEeqnarray allow the pagebreaks,
here is the code:

Code: Select all

\documentclass[12pt,a4paper]{article}
\usepackage{amsmath}
\usepackage[retainorgcmds]{IEEEtrantools}
%%%%%%
\newcommand{\integral}[2]
{\int #1 \:\mathrm{d}#2}
\newcommand{\RA}{\Rightarrow}
%%%%%
\allowdisplaybreaks[1]
\interdisplaylinepenalty=00
%%%%%%%
\newenvironment{my_alg}
{
\begin{IEEEeqnarray*}{r/r/l"r}
}
{
\end{IEEEeqnarray*}
}
%%%%%%%
\begin{document}
\begin{my_alg}
    &\integral{\frac{a+b\sin{x}}{\cos^2{x}}}{x}
          &=\integral{\left(a\sec^2{x}+b\tan{x}
        \sec{x}\right)}{x}\\
\RA &\integral{\frac{a+b\sin{x}}{\cos^2{x}}}{x}
    &=a\tan{x}+b\sec{x}+c\\
\end{my_alg}
\end{document}

Thank's Again