ClearAll; Clear[f,sf];
$DefaultFont = {"Times-Roman",10};
Needs["Graphics`Graphics`"];
upper = Plot[Log[x],{x,1,20},AxesLabel->{"x","y"},
		AxesOrigin->{0,0}, PlotRange->{{0,20.05},{0,3.05}},
		PlotLabel->FontForm["y = F(x) = ln(x)",{"Courier",10}]];
lower = Plot[1/x,{x,1,20},AxesLabel->{"x","y"},
		AxesOrigin->{0,0}, PlotRange->{{0,20.05},{0,1.05}},
		PlotLabel->FontForm["y = F'(x) = 1/x",{"Courier",10}]];

Show[GraphicsArray[{{upper},{lower}}],
		PlotLabel->"                  Figure 20.2\n\n
		The logarithm and its derivative"]