Graphics for parabolic-antenna
Graphics for parabolic-antenna
f[a_,x_]=a*x^2
Out[]=
a
2
x
f_t[a_,x_t_,x_]=(D[f[a,x],x]/.x->x_t)*(x-x_t)+f[a,x_t]
Out[]=
2a(x-x_t)x_t+a
2
x_t
f_n[a_,x_t_,x_]=-1/(D[f[a,x],x]/.x->x_t)*(x-x_t)+f[a,x_t]
Out[]=
-+a
x-x_t
2ax_t
2
x_t
In[]:=
x_0=-3/5;
plt1=Plot[{f[1,x],f_t[1,x_0,x],f_n[1,x_0,x]},{x,-1,1},PlotRange{-1/10,1},PlotStyle->{Black,{Dashed,Black},{Dashed,Black}},AxesStyle->Directive[Black,Thickness[0.004]]]
Out[]=
gpx1={Graphics[{Blue,Arrow[{{x_0,1},{x_0,f[1,x_0]}}]}],Graphics[{Blue,Arrow[{{x_0,f[1,x_0]},{0,0.25}}]}]}
Out[]=
,
Show[plt1,gpx1]
Out[]=
