(PUC) Dada a função $f(x)\,=\,\left\{ \begin{array}{rcr} 3^{-x} - 1\; & \mbox{, se } -1 \leqslant x < 0 \\ tg(\frac{x}{2})\; & \mbox{, se } \; 0 \leqslant x < \pi \phantom{X}\\ {\large \frac{x}{x^2 - 2}}\; & \mbox{, se } \; \pi \leqslant x \leqslant 6\phantom{X} \\ \end{array}\right. \;\;$
então $\,f(-1)\,$,$\,f(\frac{\pi}{2})\,$ e$\,f(4)\,$ são, respectivamente
a)
$2, \, 1, \,{\large \frac{2}{7}}$
b)
$1, \, 3, \, {\large \frac{2}{3}}$
c)
$2, \, 3, \, {\large \frac{1}{2}}$
d)
$3, \, 2, \,{\large \frac{-1}{2}}$
e)
${\large \frac{1}{2}}, \, 1, \, 2 $
