实验3观察 2x的极限 In (xy)-00)x2+y 程序: 印x,y]=2*x^3/(x^2+y^2)cont={-08,-0.4,0.2,-0.1,-0050.05,0.10.2,0.4,0.8} ContourPlot[fx,y],x,-1, 1, y-1, 1), Contours->cont PlotPoints->50, Color Function->Hue Print[fx,y]=, fx, y]]; Print["]; Print[fx, y]==c, "where" ]; Print[c=", cont 结果实验3 观察 的极限 程序： f[x_,y_]=2*x^3/(x^2+y^2);cont={-0.8,-0.4,-0.2,-0.1,-0.05,0.05,0.1,0.2,0.4,0.8}; ContourPlot[f[x,y],{x,-1,1},{y,-1,1},Contours->cont, PlotPoints->50,ColorFunction->Hue]; Print["f[x,y]=",f[x,y]];Print[""];Print[f[x,y]==c," where"];Print["c=",cont] 结果：