I am trying to see the asymptotics of the Var function as below, from the plot it seems it goes to $-\infty$, however, I also calculate its asymptotics which gives me a positive $+\infty$.. Why could this happen?
Here is my code:
ClearAll["Global`*"];
C0=1;C1 = 1; C2 = 1; C3 = Sqrt[2];
g=1/(Log[n])^(1/20);
p = (2*C1 + C2)/(2*(C1 + C2 - C3)) - Sqrt[C2^2 + 4*C1*C3]/(2*(C1 + C2 - C3)) + g;
VarianceF[n_]:= 16*C0^2*(p) - 16*C0^2*(p)^2 + ((C1^2 + C3^2)/2)*n*(p) - ((C1^2 + C3^2)/2)*n*(p)^2 - (C1^2 + C3^2)*(p) + (C1^2 + C3^2)*(p)^2 -4*C2^2*n*p^4 + 8*C2^2*p^4 - 6*C2^2*n*p^2 + 12*C2^2*p^2 + 2*C2^2*n*p - 4*C2^2*p + 8*C2^2*n*p^3 - 16*C2^2*p^3;
Plot[VarianceF[n], {n, 2, 10^10}, PlotRange -> All]
Asymptotic[VarianceF[n],n->Infinity]
Limit[VarianceF[n],n->Infinity]
Here is the output: