ClearAll;
$DefaultFont = {"Times-Roman",10};
Needs["Graphics`Graphics`"];
usw = 2 + Sqrt[2];
g1[u_]:= u/(1+u);
g2a[u_]:= u(4 - 3 u + 2 Sqrt[2] (u-1))/2;
g2[u_]:= Which[u <= N[usw],g2a[u],u >= N[usw],1];
hor = Graphics[{Dashing[{0.01,0.01}],Line[{{0,1},{10,1}}]}];

plotb = Plot[g2[u],{u,0,10},
	PlotRange->{{0,10},{0,1.05}}];
plota = Plot[g1[u],{u,0,10},AxesLabel->{"u = x/B","z = y/A"},
	PlotStyle -> Dashing[{0.001,0.01}],
	PlotLabel -> "z = K(u)  OR  y = Q(x)",
	PlotRange->{{0,10},{0,1.05}}];
plot = Show[plota,hor,plotb];

Show[GraphicsArray[{{plot}}],
	PlotLabel->"Figure 4.2"]