\input arrows.tex
$$
\vcenter {
\def \hfq {\hfil \ }
\offinterlineskip
\halign {
&\hfq #\hfq
\cr
$t$& \vrule depth 5pt &
$-\infty $&& $-7/3$&& $0$&& $1$&& $+\infty $&
\cr
\noalign{\hrule}
$x' (t)$& \vrule height 10pt depth 3pt &
& $-$& $\approx -9, 33$& $-$& $0$& $+$& $1$& $+$&&
\cr
\noalign{\hrule}
\bbuucenter{$x (t)$}& \vrule&
\bbuup{$+\infty $}&
\bbup{\brightdownarrow} & \bup{$\approx 14, 9$}&
\brightdownarrow & \down{$4\strut $}&
\bbrightuparrow & \bbup{$6$}& \bbup {\bbrightuparrow }& \bbup {\bbup {$+\infty $}}
\cr
\noalign{\hrule}
$y' (t)$& \vrule height 10pt depth 3pt &
& $+$& $0$& $-$& $-7$& $-$& $0$& $+$&&
\cr
\noalign{\hrule}
\bbuucenter{$y (t)$}& \vrule&
\down {$-\infty $}&
\brightuuparrow & \bbuup {$\approx 18, 52$}&
\bbup {\brightdownarrow }& \bbup {$4$}&
\brightdownarrow & \down{$0$}&
\bbrightuuparrow & \bbuup{$+\infty $}
\cr
}}
$$
\bye

—
Syracuse — Dernière modification : 11 février 2002 (0.06s - 3946087 - 8 janvier 2009)