\input arroaws.tex
$$\vcenter {\offinterlineskip
\def \cc#1{ \hfil #1 \hfil }
\halign {
\cc {$#$}& #\tv && \cc {$#$}
\cr
x&& 0&&& e^{1/2}&& +\infty
\cr
\noalign {\hrule height 1pt }
1 - 2\ln x&& && +& 0& -
\cr
\noalign {\hrule }
x^2&& 0&& +& \tv & +
\cr
\noalign {\hrule height 1pt}
f' (x)&& \doublevrule && +& 0& -
\cr
\noalign {\hrule height 1pt}
\buucenter {$f (x)$}&&
\doublevrule &
\down {$-\infty $}&
\brightuuparrow & \buup {$2(e^{-1/2}-1) \approx -0, 79$}&
\brightddownarrow & \down {$-2$}
\cr
}}
$$
\bye

—
Syracuse — Dernière modification : 11 février 2002 (0.08s - 3946253 - 8 janvier 2009)