Math & Science ⇒ What is wrong with this?

[charlejs]

I'm new to Latex and all it's glory.
What am I doing wrong here?

\begin{eqnarray}
\left[ \begin{array}{c}
C_{\alpha}^{+} (x_o +\ell) \\
. \\
. \\
_____ \\
C_{\alpha}^{-} (x_o) \\
. \\
. \\
\end{array} \right]

[Stefan Kottwitz]

Hi charlejs,

welcome to the board!

• you used _____, however the underscore _ has a meaning in LaTeX for writing subscripts
• you forgot to close the eqnarray environment
• the code is incomplete, \documentclass missing etc.
• you don't need eqnarray for a simple expression with an array
• eqnarray is obsolete, see eqnarray vs. align
• you could use a matrix environment instead of array

Example:

Code: Select all

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\[
  \begin{bmatrix}
    C_{\alpha}^{+} (x_o +\ell) \\
    . \\
    . \\
    . \\
    C_{\alpha}^{-} (x_o) \\
    . \\
    . \\
  \end{bmatrix}
\]
\end{document}

Stefan

[charlejs]

Thanks for the response. I'll look at using the bmatrix structure that you gave me the example for. I have plenty of matrices to write. And good to know eqnarray is obsolete. Some background, I'm making changes to a 9 year old Latex document.