II-d-c.tex

$$\vcenter {\offinterlineskip
    \def \cc#1{ \hfil #1 \hfil }
    \halign {
    \tvg \cc {$#$}& #\tv & \cc {$#$} & \cc {$#$}& \cc {$#$}&
\cc {$#$}& \cc {$#$}& \cc {$#$}&#\tv
    \cr
    \noalign {\hrule}
        x&& 0&&& 2&& +\infty&
    \cr
    \noalign {\hrule}
    f'(x)&& \doublevrule && -& 0& +&&
    \cr
    \noalign {\hrule}
    \buuucenter {$f(x)$} && \doublevrule &\bbuup{1} &\bbrightddownarrow 
    & \down {0}&\bbrightuuparrow &\bbuup {$-2$}&
    \cr
    \noalign {\hrule}
    }}
$$