# numerical integration – NIntegrate and MaxRecursion

I’m using `NIntegrate` to get the value of a very complicated function `f[k,T,M]`, where `T` and `M` are some parameters:

``````S[T_, M_, MaxRec_]:= NIntegrate[f[k, T, M], {k,0,Infinity}, PrecisionGoal->10, MaxRecursion->MaxRec]
``````

What puzzles me is the fact that, for the same parameters, I get different values depending on `MaxRec`:

``````S[10^12, 10^12, 10]
``````

``````1.30494*10^30
``````

versus

``````S[10^12, 10^12, 50]
``````

``````-1.161*10^45
``````

How should I interpret these results? I could provide the explicit form of `f` if needed. Thanks a lot!