Re: Math help needed

[Tobias Burnus <tobias.burnus@physik.fu-berlin.de>]

Hi Bruce,

On Sun, 3 Feb 2002, Bruce Horrocks wrote:
> Is there a math manual available? (I couldn't find one)
Unfortunally no good math manual exists for ConTeXt, but one can use
(nearly) all plain TeX commands.

> For example, how can I do the following plain TeX in ConTeX:
> $$\eqalignno{\sin(x)^2 &= 1-\cos(x)^2 &(1) \cr
>              \noalign{\hbox{and also}}
>              \cos(x)^2 &= 1-\sin(x)^2 &(2) \cr}$$
Your plain TeX version works, but how about this:
(ConTeXt used to count, noalign doesn't need a(n extra) \hbox{})

\placeformula
\startformula
\eqalignno{
  \sin^2 x &= 1-\cos^2 x & \formulanumber[sin]\cr
\noalign{and also}
  \cos^2 x &= 1-\sin^2 x & \formulanumber[cos]\cr
}\stopformula

or alternative:

\placeformula[cos-sin]
\startformula
\eqalignno{
  \sin^2 x &= 1-\cos^2 x & \formulanumber[sin2]{a}\cr
\noalign{and also}
  \cos^2 x &= 1-\sin^2 x & \subformulanumber[cos2]{b}\cr
}\stopformula

Then you can refer to these equation by using:
\in[sin] produces 1
\in[cos] produces 2
\in[cos-sin] produces 3
\in[sin2] produces 3a
\in[cos2] produces 3b

Tobias