\input arrows.tex
$$
\vcenter{
\def \hfq{\hfil \ }
\offinterlineskip
\halign{
&\hfq #\hfq
\cr
$t$& \vrule depth 5pt &
$-1$&& $0$&& $1$&& $2$&
\cr
\noalign{\hrule}
$x' (t)$& \vrule height 10pt depth 3pt &
$-2$& $-$& $0$& $+$& $2$& $+$& $4$&
\cr
\noalign{\hrule}
\bbuucenter{$x (t)$}& \vrule&
\bbup{$2$}&
\brightdownarrow & \down{$1\strut $}&
\brightuparrow & \bup{$2$}&
\bup{\brightuparrow} & \bup{\bup{$5$}}
\cr
\noalign{\hrule}
$y' (t)$& \vrule height 10pt depth 3pt &
$-4$& $-$& $-2$& $-$& $0$& $+$& $2$&
\cr
\noalign{\hrule}
\bbuucenter{$x (t)$}& \vrule&
\bbuup{$5$}&
\bbup{\brightdownarrow} & \bup{$2$}&
\brightdownarrow & \down{$1$}&
\bbrightuparrow & \bbup{$2$}
\cr
}}
$$
\bye

—
Syracuse — Dernière modification : 11 février 2002 (0.09s - 3946002 - 7 janvier 2009)