Assume these parameter definitions first:
P0 = 325000000000000000000000000000000/1289899878039;
th = 22 10^-7;
alpha = 15*^6;
p0value = 0.0000697013247924021100000;
Lh = 5 10^-9;
d = 80 10^-9;
A = -2.8490639736294850547486980507937310695688037435690471`40.25650391588118*^\
14;
B = 1.1760120752241583305643404927085980980404601631188207268`37.\
974790074939705*^26;
Define two functions
tmp[x_] := A E^(x/Lh) + B E^(-x/Lh) + p0value ;
tmp2[x_] := -(alpha P0 th)/(1 - alpha^2 Lh^2) E^(-alpha x);
Subtracting them at x=d yields the small number p0value
tmp[d] - tmp2[d]
0.000069701324792402
I want the plot of tmp[x] - tmp2[x] to have a value of p0value (0.0000697013247924021100000) at x = d and not to stop at $10^{20}$.
LogPlot[{tmp[x] - tmp2[x]}, {x, 0, d}, PlotRange -> {{0, d}, {10^-5, 10^25}}]

I tried MeshFunctions but without success. Can anyone give me a hint?


