>>440
f1[x_] := x^2; x1 = 1.9; offset1 = {1.2, 0};
label1 = "二次関数"; grayLevel1 = GrayLevel[0.6];

f2[x_] := x; x2 = 1.8; offset2 = {1.2, 0};
label2 = "一次関数"; grayLevel2 = GrayLevel[0.3];

f3[x_] := Sqrt[x]; x3 = 1.4; offset3 = {-1, 0.4};
label3 = "無理関数"; grayLevel3 = GrayLevel[0];

boxLeft = 2.2; boxTop = 4; boxHeight = 1.2; boxWidth = 1.4;

graphLabel[f_, pt_, offset_] :=
Text["y=" <> ToString[InputForm[f[x]]], {pt, f[pt]}, offset]

graphTableLabel[position_, tableLabel_] :=
Text[tableLabel, position, {-1, 0}];

g = Plot[{f1[x], f2[x], f3[x]}, {x, 0, 2}, DisplayFunction->Identity,
PlotStyle->{{grayLevel1}, {grayLevel2}, {grayLevel3}}];