Re: Ambiguity of "Plot"

*To*: mathgroup at smc.vnet.net*Subject*: [mg127808] Re: Ambiguity of "Plot"*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Thu, 23 Aug 2012 20:49:34 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net*References*: <20120823065423.92A8A6844@smc.vnet.net>

You don't have correct Mathematica syntax to denote functions. Did you look at the many examples provided in the documentation? or make use of the Classroom Palette, say, to get a template for Plot? First, you need: f[\[Alpha]_] := =85 where the argument is enclosed in square brackets rather than parentheses and where you need to indicate that \[Alpha] is a pattern variable by using the underscore character after it. Second, in the Plot expression, you need again to use square brackets to surround the argument, that is, use f[\[Alpha]] instead of parentheses. Third, to denote the plot domain, for the second argument to Plot you have to use the list { \[Alpha], 0, 1} like that rather than including the inequality 0 < \[Alpha] < 1 After those ecorrections, of course you need to give a numerical values to the parameters \[Rho] and \[Delta] before having any hope of obtaining any plot whatsoever. On Aug 23, 2012, at 2:54 AM, JikaiRF at aol.com wrote: > I have been embarrassed about a function Plot. > I would like to plot a curve defined as follows: > > f(\[Alpha]) = (\[Rho] + \[Delta] - \[Delta] \[Alpha] - Sqrt[\[Delta]\[Rho] \ > \[Alpha] (1 - \[Alpha]) + \[Rho]^2 \[Alpha]])/((\[Rho] + \[Delta]) (1 \ > - \[Alpha])). > Here, 0 < \[Alpha] < 1. > > And I programmed in this way; > Plot[f(\[Alpha]), { \[Alpha], 0 < \[Alpha] < 1}] > > The curve I obtained from Mathematica is monotonously decreasing. AS a result, f(1) =0. > However, by using l'H=F4pital7 theorem, f(1) = 1/2 is correct. > In this situation, I would like to obtain an accurate curve. --- Murray Eisenberg murray at math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2859 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305

**References**:**Ambiguity of "Plot"***From:*JikaiRF@aol.com