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Re: wrong limit ?
First of all, I suspect you meant Limit[Coth[x B], B -> +Infinity] not Limit[Coth[xB], B -> +Infinity] There's a very big difference. Secondly, the limit doesn't exist for ANY non-zero B, since Limit[Coth[x], x -> -Infinity] -1 Limit[Coth[x], x -> Infinity] 1 and letting x approach +/- 1/B Infinity makes x B approach +/- Infinity = = (on the real line). Bobby On Sat, 26 May 2007 03:43:44 -0500, ventu <nuclearVentu at gmail.com> wrote= : > Hi ! > Here's my problem (mathematica 5.0,5.1,5.2): > > Limit[Coth[xB], B -> +Infinity] > > it doesn't understand. > mmh. ok I try then: > > Limit[Coth[x B], B -> +Infinity, Assumptions -> Im[x] == 0] > > 1 > > WRONG ! In fact: > > Limit[Coth[x B], B -> +Infinity, Assumptions -> Im[x] == 0 && Re[= x] < > 0] > > -1 > > Indeed the correct result should be sign(x). And I couldn't find a way= > to get it right. > Do I mistake something? > > Thank you in advance, > > Davide > > > -- = DrMajorBob at bigfoot.com