Re: What's in an expression?

• To: mathgroup at smc.vnet.net
• Subject: [mg132418] Re: What's in an expression?
• From: Murray Eisenberg <murray at math.umass.edu>
• Date: Tue, 11 Mar 2014 03:36:28 -0400 (EDT)
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```One way, which doesn't involve looking at the form of the student's
symbolic answer, is something employed by a at least one of the popular
on-line homework systems: evaluate the "correct" answer at a number of
judiciously chosen numerical values of x, evaluate the student's answer
at the same values of x, and check that they're the same (within fuzz).

Otherwise, you may have to deal with a myriad of possible forms in which
the student might submit an answer without actually doing what you want.

On Mar 10, 2014, at 4:38 AM, sam.takoy at yahoo.com wrote:

> Hi all,
>
> I'm building a little Mathematica system that checks answers entered
by students. Suppose the question is "what is Sin'[x]?" ad the student
responds: Sin'[x] which is "correct", but not the intended answer
(Cos[x]). I'm wondering if there is a general way to approach this sort
of problem. In particular, is there a way to find out whether a given
expression includes certain elements (like Derivative)?
>
>
> Sam
>

Murray Eisenberg                                murray at math.umass.edu
Mathematics & Statistics Dept.
Lederle Graduate Research Tower      phone 240 246-7240 (H)
University of Massachusetts
710 North Pleasant Street
Amherst, MA 01003-9305

```

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