🚀 go-pugleaf

Michael De Nil wrote:

> Heyz
> 
> someone who knows how to add a newline after a math-expression ?
> currently, I always \end{displaymath} and \begin{displaymath} to add a
> newline...
> 
> anyone plz ?
> michael

If I'm going to have multiple lines of math, I use the eqnarray or 
eqnarray* environments.  (The * version doesn't number the lines.  The 
unstarred version numbers all lines that don't have the \nonumber command 
in them.)  It's automatically formatted as three columns, assuming the 
relation (=, <, >, etc.) is the second column.  Columns are separated by &, 
and newlines are made with \\.  Here's an example of the derivation of the 
quadratic equation:

Given \[Ax^2+Bx+C=0\] what is $x$?

We begin by defining $b=\frac{B}{A}$ and $c=\frac{C}{A}$.  This allows
us to rewrite the expression as
\[
x^2 + bx+c = 0
\]

Now, we remember that $\left(p+q\right)^2=p^2+2pq+q^2$, and apply this
to the expression.
\begin{eqnarray}
x^2 + bx + \frac{b^2}{4} -\frac{b^2}{4} +c &=&0\nonumber\\
\left(x+\frac{b}{2}\right)^2 &=& \frac{b^2}{4} - c\nonumber\\
x+\frac{b}{2} &=& \pm \sqrt{\frac{b^2}{4}-c}\nonumber\\
x &=& -\frac{b}{2} \pm \sqrt{\frac{b^2}{4}-c}\nonumber\\
x &=& \frac{B}{2A} \pm
\sqrt{\frac{B^2}{4A^2}-\frac{C}{A}}\nonumber\\
x &=& \frac{-B\pm\sqrt{B^2-4AC}}{2A}
\end{eqnarray}

(This is the one I posted on http://planetmath.org a few months ago.)

-- 
- Blaine

http://www.bureau42.com
ICQ: 24893016
XFW # 299792458, WM, SW, WNS, NRMTPB, FPSSG
Koopa TROoPA #42

Michael De Nil wrote:

> Heyz
>
> someone who knows how to add a newline after a math-expression ?
> currently, I always \end{displaymath} and \begin{displaymath} to add a
> newline...
>
> anyone plz ?
>         michael
>
> -----------------------------------------------------------------------
>                 Michael De Nil -- michael@aerythmic.be
>        Linux LiSa 2.4.18 #4 SMP ma apr 1 11:11:48 CEST 2002 i686
>   20:46:01 up 2 days, 50 min,  6 users,  load average: 1.00, 0.78, 0.37
> -----------------------------------------------------------------------

when you're writing math always use the amsmath package.

And do not! use the eqnarray environment (it has a few bugs)

use instead align (or align*)

\begin{align*}
a&=b=c\\
&=n=m
\end{align*}
then the character just after the & will be aligns under each other.

Also have a look at

ftp://ftp.ams.org/pub/tex/doc/amsmath/short-math-guide.ps

(or the .pdf version)
it's a short introduction to some of the things that can be done with the
amsmath package

it's also a good idea to have a look at the 'news' version of chapter 8 of
The LaTeX Companion

http://www.ctan.org/tex-archive/info/companion-rev/ch8.ps


--

/daleif
F2.10 - Institut for Matematiske Fag, Matematisk Afdeling
�rhus Universitet