ClearAll;
$DefaultFont = {"Times-Roman",12};
Needs["Graphics`Graphics`"];

xmax = 3; eticks = {5, 10, 15, 20}; lticks = {1, 2, 3};

expplot = Plot[E^x,{x,0,xmax},
		AxesLabel -> {"x","y"},
		PlotLabel -> "(a) y = exp(x)",
		Ticks->{lticks,eticks}];
logplot = Plot[Log[x],{x,1,E^xmax},
		AxesLabel -> {"y","x"},
		PlotLabel -> "(b) x = ln(y)",
		Ticks->{eticks,lticks}];
Show[GraphicsArray[{{expplot},{logplot}}],PlotLabel -> "Figure 7.4"]