z08 a fourier变nb7 Clear [f, g] g[k Pot[【x,1],q【x,1],(x,-9,9}, Plotsty1e→{Rd),(B1ue, Dashing [o.02] AxesLabel -(None, style["a=l", 14]), PlotRange+[0, 1.11, PlotLegends→ Placed LineLegend[style"f(x)",FontFamily+"Times",Italic,Bold,10] style["f(k)",FontFamily +"Times", Italic, Bold, 10F egendMarkersize+(22,1),(Scaled[[68, 0.6)1,(0,0.2))1 g2=Plot[(f[x, 51, g[x, 51),(x,-9, 9), Plotstyle+(Red,(Blue,Dashing[o021)) Axeslabe1→{None,sty1e【"a=5",14]},P1 legends→ Placed [LineLegend[style["f(x)",FontFamily+"Times",Italic,Bold,10] e["f(k)",FontFamily+"Times", Italic, Bold, 10F LegendMarkersize+(22, 1),(Scaled[(68,0.6), (0,0.2)31 Grid[[igl, Spacer[5], g2]]] a=5 f(k)Clear[f, g]; f[x_, a_] := Exp[- a x2]; g[k_, a_] := π α Exp- k2  (4 a) g1 = Plot{f[x, 1], g[x, 1]}, {x, -9, 9}, PlotStyle  {{Red}, {Blue, Dashing[0.02]}}, AxesLabel  {None, Style["α=1", 14]}, PlotRange  {0, 1.1}, PlotLegends  PlacedLineLegendStyle["f(x)", FontFamily  "Times", Italic, Bold, 10], Style"f  (k)", FontFamily  "Times", Italic, Bold, 10, LegendMarkerSize  {22, 1}, {Scaled[{.68, 0.6}], {0, 0.2}}; g2 = Plot{f[x, 5], g[x, 5]}, {x, -9, 9}, PlotStyle  {Red, {Blue, Dashing[0.02]}}, AxesLabel  {None, Style["α=5", 14]}, PlotLegends  PlacedLineLegendStyle["f(x)", FontFamily  "Times", Italic, Bold, 10], Style"f  (k)", FontFamily  "Times", Italic, Bold, 10, LegendMarkerSize  {22, 1}, {Scaled[{.68, 0.6}], {0, 0.2}}; Grid[{{g1, Spacer[5], g2}}] f(x) f  (k) -5 0 5 0.2 0.4 0.6 0.8 1.0 α=1 f(x) f  (k) -5 5 0.2 0.4 0.6 0.8 1.0 α=5 E(x, y) = -∞ ∞ -w0 2 α2/4  (α x +β y) α, β = k2 - α2 , k = 2 π λ z08a Fourier 变换.nb 7