Re: Is this normal for Limit?

*To*: mathgroup at smc.vnet.net*Subject*: [mg82270] Re: [mg82241] Is this normal for Limit?*From*: Andrzej Kozlowski <akoz at mimuw.edu.pl>*Date*: Wed, 17 Oct 2007 03:45:47 -0400 (EDT)*References*: <200710160723.DAA08676@smc.vnet.net>

On 16 Oct 2007, at 16:23, Michael Mandelberg wrote: > I have what I would think is the following simple limit to evaluate: > > $Pre = Refine[#] &; > $Assumptions = {t \[Element] Reals, k \[Element] Reals, k > 0}; > > In[3]:= Limit[Exp[-k t], t -> Infinity] > > The results is: > > Out[3]= Limit[\[ExponentialE]^(-k t), t -> \[Infinity]] > > In other words Mathematica 6.0.0 punts on this. Is there any sense in > which this limit is not well-defined? > > Michael Mandelberg > > $Assumptions is not working properly. I think this has already been pointed out on this list a while ago. Limit[E^((-k)*t), t -> Infinity, Assumptions -> k > 0] 0 Andrzej Kozlowski

**References**:**Is this normal for Limit?***From:*Michael Mandelberg <mmandelberg@comcast.net>