Graphical representation is an extremely important aid $($a picture is worth a thousand

words$).$ We will use gnuplot to read the file and draw the graph. For example, suppose

we want to display a graph of a parabola with the file data$1.$dat looking likethis:

$-1\mathrm{.}0000-6\mathrm{.}4000$

$-0\mathrm{.}9000-5\mathrm{.}1060$

$-0\mathrm{.}8000-3\mathrm{.}9240$

$-0\mathrm{.}7000-2\mathrm{.}8540$

$2\mathrm{.}7000-33\mathrm{.}1140$

$2\mathrm{.}8000-35\mathrm{.}9640$

$2\mathrm{.}9000-38\mathrm{.}9260$

$3\mathrm{.}0000-42\mathrm{.}0000$