Re: Interesting problem looking for a solution.

*To*: mathgroup at smc.vnet.net*Subject*: [mg122082] Re: Interesting problem looking for a solution.*From*: DrMajorBob <btreat1 at austin.rr.com>*Date*: Wed, 12 Oct 2011 03:44:39 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <j6rk1f$1nr$1@smc.vnet.net> <201110100826.EAA15321@smc.vnet.net>*Reply-to*: drmajorbob at yahoo.com

He'd also need to know the random number chosen, would he not? Bobby On Tue, 11 Oct 2011 03:25:49 -0500, Murray Eisenberg <murray at math.umass.edu> wrote: > With that proposed solution, all the student needs to do to see the > function's definition is to open the closed cell. > > Very low security! > > On 10/10/11 4:26 AM, Dr. Wolfgang Hintze wrote: >> "Church, Gary"<churchg at smccd.edu> schrieb im Newsbeitrag >> news:j6rk1f$1nr$1 at smc.vnet.net... >>> Hello, >>> >>> I have an (I think) interesting problem for you Mathematica gurus. >>> >>> I'm trying to create a worksheet for my students and want to be able >>> to display the plot of a randomly generated function f[x], without >>> them being able to access the expression which defines f; In other >>> words, I don't want them to be able to evaluate f[x]. >>> >>> The idea is that each student will get a different function f[x] and >>> will see a different graph and they have to determine the expression >>> which defines f. They then have to plot the function they think is f >>> against the actual function f[x] and turn in the two plots (or the >>> one plot with the two graphs.) >>> >>> Is this possible? >>> >>> Thanks much, >>> Gary >>> >> >> Are you looking for something like this? >> To begin with, define the list lf of possible functions. >> Then select a definition for f[x] at random from the list, and finally >> plot it. >> Repeat the second step (In[219]) as often as you (and your students) >> like. >> >> In[221]:= >> lf = {x^2, Sin[x], Exp[-x]}; >> >> >> In[219]:= >> f[x_] = lf[[Random[Integer, {1, 2}]]]; >> Plot[f[x], {x, 0, 5}]; >> >> If you wish to keep the list secret your can hide it from being viewed >> using the option inspector of the cell (right click> General >> Properties> Cell Open set to false> Apply). >> >> Hope this helps >> Wolfgang >> >> > -- DrMajorBob at yahoo.com

**References**:**Re: Interesting problem looking for a solution.***From:*"Dr. Wolfgang Hintze" <weh@snafu.de>