Re: Re: Limit[(x - Log[Cosh ]) SinIntegral , x -> Infinity]

*To*: mathgroup at smc.vnet.net*Subject*: [mg87005] Re: [mg86947] Re: Limit[(x - Log[Cosh ]) SinIntegral , x -> Infinity]*From*: Daniel Lichtblau <danl at wolfram.com>*Date*: Fri, 28 Mar 2008 03:19:00 -0500 (EST)*References*: <20080326082007.401$ci@newsreader.com> <200803271316.IAA19623@smc.vnet.net>

Szabolcs HorvÃ¡t wrote: > On Wed, Mar 26, 2008 at 1:20 PM, David W. Cantrell > <DWCantrell at sigmaxi.net> wrote: > >> I confirm the precise behavior you described. It's surprising that a >> restart was required. > > > Actually a ClearSystemCache[] is enough, but since cached results can > affect the success of calculations, probably it would be better if > Mathematica did not cache the "result" that it *cannot* calculate > something. > [...] I beg to differ. If that nonevaluation result is time consuming to compute, and is something that might show up in a context where recomputation is an issue, then caching can save considerable time. Limits tend to be recomputed when one does, say, a definite integral requiring several different tactics. Caching them thus can reduce timings of Integrate, a notoriously slow function. Daniel Lichtblau Wolfram Research

**References**:**Re: Limit[(x - Log[Cosh[x]]) SinIntegral[x], x -> Infinity]***From:*"Szabolcs HorvÃt" <szhorvat@gmail.com>