TeX source:

\begin{array}{l|l|l} x & y=x^{2} & \begin{array}{l} \text { slope of line through } \\ (\mathrm{x}, \mathrm{y}) \text { and }(2,4) \end{array} \\ \hline 3 & 9 & 5 \\ 2.5 & 6.25 & 4.5 \\ 2.01 & 4.0401 & 4.01 \end{array}