Re: Calculus : limits

*To*: mathgroup at smc.vnet.net*Subject*: [mg51310] Re: Calculus : limits*From*: p-valko at tamu.edu (Peter Valko)*Date*: Thu, 14 Oct 2004 06:35:39 -0400 (EDT)*References*: <ckfs34$isl$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Strictly speaking Direction option has to be specified. The default is "Automatic" but in this case Mathematica takes (seemingly) Direction-> -1 as default. Limit[(Abs[Sin[x]-Sin[2 x]]) / x, x->0,Direction->-1] Limit[(Abs[Sin[x]-Sin[2 x]]) / x, x->0,Direction->1] will give you two right answers (that are not equal.) The truth of the matter is, that Calculus-type functions do not handle Abs very well and if possible I use other things, e.g. UnitStep. P. Amir <z64043 at netscape.net> wrote in message news:<ckfs34$isl$1 at smc.vnet.net>... > Hi, > > I'd like to find the limit of > Limit[(Abs[Sin[x]-Sin[2 x]]) / x, x->0] > > I use Mathematica v.5. I get the wrong (??) answer : 1 > > While I try to display the graph of this function by using "Plot", it > seems that there is no limit at the point x=0. > Please help... > > Amir