4

I am currently having issues with the display of this equation below.

The code I have inserted is using align but I have also tried using eqnarray, (which has right-alignment but is deprecated), and am now at the point of considering using a table.

The alignment here doesn't appear to do as the documentation says, and when I add extra &'s I can get the format slightly better but not exactly as I want. To be clear, it is the right-alignment of the second column that is giving me most trouble.

Code:

\begin{align*}
&\frac{2^{1+k/2}}{k!} &< 1\\
\Leftrightarrow &2^{1+k/2} &< k!\\
\Leftrightarrow& (\sqrt{2})^k\cdot 2 &< \left(\frac{k}{e}\right)^k \sqrt{2 \pi k}
\end{align*}

What it looks like now:

enter image description here

What I want it to look like:

enter image description here

migrated from stackoverflow.com Feb 5 '13 at 13:17

This question came from our site for professional and enthusiast programmers.

5

Following is the appropriate way to have multiple alignments within an align:

enter image description here

\documentclass{article}
\usepackage{amsmath}% http://ctan.org/pkg/amsmath
\begin{document}
% Original
\begin{align*}
 & \frac{2^{1+k/2}}{k!} & < 1\\
\Leftrightarrow & 2^{1+k/2} & < k!\\
\Leftrightarrow & (\sqrt{2})^k\cdot 2 & < \left(\frac{k}{e}\right)^k \sqrt{2 \pi k}
\end{align*}
% Correct
\begin{align*}
 && \frac{2^{1+k/2}}{k!} & < 1\\
\Leftrightarrow && 2^{1+k/2} & < k!\\
\Leftrightarrow && (\sqrt{2})^k\cdot 2 & < \left(\frac{k}{e}\right)^k \sqrt{2 \pi k}
\end{align*}
\end{document}

As reference for multiple points within align, see the amsmath user guide (section 3.6 Equation groups with mutual alignment, p 6-7). There's also other align-related environments that would yield this output, including alignat.

Regarding your venture to other environments, perhaps \eqnarray vs \align is of interest.

  • Great info, thanks very much for this as well as editing my original post – Max Steele Feb 4 '13 at 19:26

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.