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\begin{aligned} &\begin{array}{l|l} {\mathrm{x}} & {\mathrm{f}(\mathrm{x})} \\ \\ \hline 3.1 & 7.2 \\ 3.004 & 7.008 \\ 3.0001 & 7.0002 \\ 3.000002 & 7.000004 \end{array}\\ &\begin{array}{ll}\qquad \downarrow & \qquad \qquad \downarrow \\ \qquad 3 & \qquad \qquad 7 \end{array} \end{aligned}