Re: Log(ln) Function + 2 Parameters + Greater

*To*: mathgroup at smc.vnet.net*Subject*: [mg89298] Re: Log(ln) Function + 2 Parameters + Greater*From*: Jerry <Jer75811 at yahoo.com>*Date*: Wed, 4 Jun 2008 05:37:38 -0400 (EDT)*References*: <g22tp5$ikl$1@smc.vnet.net> <g237c4$q2n$1@smc.vnet.net>

Sir, I have never seen a function definition in the form you give: f[a_][x_] := x (a + Log[x])^2 After a bit of playing with it, I don't see the difference between this and f[a_,x_] := x (a + Log[x])^2 I really don't know how to search in help for this f[a_][x_] form. Can you tell me if there is any essential difference? Thank you. David Park wrote: > First, define your f function with a as a parameter. > > f[a_][x_] := x (a + Log[x])^2 > > Mathematica can't make a plot unless it knows values for a. Of course, it > won't plot any results for x < 0 and I'm not certain if you actually meant x > > 0 rather than a > 0. In any case, you can use any real domain for a. Here > is a plot for a specific value of a. > > Plot[f[2][x], {x, -5, 5}, > AxesLabel -> {x, f}] > > You can look at an extended a domain by using Plot3D. > > Plot3D[f[a][x], {a, -5, 5}, {x, 0, 5}, > PlotRange -> All, > AxesLabel -> {a, x, f}] > > Another approach is to use a Manipulate statement with a controlled by a > slider. > > Manipulate[ > Plot[f[a][x], {x, 0, 5}, > PlotRange -> {0, 250}, > AxesLabel -> {x, f}], > Style[Row[{HoldForm[f["a"][x]] == f["a"][x]}], 16], > Delimiter, > {a, -5, 5, Appearance -> "Labeled"}] > > >

**Follow-Ups**:**Re: Re: Log(ln) Function + 2 Parameters + Greater***From:*Murray Eisenberg <murray@math.umass.edu>