[LON-CAPA-users] alternate notation

[Peter Riegler]

Hi Justin,

is it something like the following that you have in mind? There
o ln(y^n)
o n*ln(y)
o log(y^n)
o n*log(y)
o and stuff like n/2*ln(y^2)
will be correct answers.

Peter

<problem>
<script type="loncapa/perl">
$n = &random(2,5,1);
$var = "y"; #could be randomized
$rhs = "$var^$n";
$sol = "$n ln($var)"; #preferably to be determined computationally
</script>

<startouttext />
Solve for <m>$ x $</m>: <m eval="on">$ \exp(x) = $rhs $</m><br/>
x =
<endouttext />

<mathresponse answerdisplay="$sol" cas="maxima" args="$rhs">

<answer>
rhs: LONCAPALIST[1];
ln(x):= log(x);
sol: ln(rhs);
is( RESPONSE[1] = sol);
</answer>

<textline readonly="no" size="50" />
</mathresponse>

</problem>

Peter Riegler wrote:
> Hi Justin,
> 
> we solve this kind of problems by telling maxima how to handle ln. This 
> requires the use of mathresponse (formularesponse uses maxima, but does 
> not allow you to write maxima code for grading).
> 
> You could for instance define ln
> 
> <mathresponse answerdisplay="$F" cas="maxima" args="@args" id="11">
>   <answer>
>   ln(x):= log(x);
>   is ( RESPONSE[1]=LONCAPALIST[1] );
>   </answer>
>   ...
> 
> or substitute
> 
> <mathresponse answerdisplay="$F" cas="maxima" args="@args" id="11">
>   <answer>
>   is ( subst(log,ln,RESPONSE[1]=LONCAPALIST[1]) );
>   </answer>
> 
> In both examples $args[0]=LONCAPALIST[1] contains the correct answer.
> 
> I hope this will help
> 
> Peter
> 
> 
> Justin Gray wrote:
>> I seem to recall that there is a way to specify an alternate notation 
>> within the <script> tags of a problem, but cannot recall how to do 
>> this. If a student submits an answer using natural logs with the 
>> notation ln, how can I replace ln with log in their answer so that 
>> Maxima will understand it?
>>
>> Thanks,
>> Justin
>>
>> P.S. I know that I can specify a collection of answers in formula 
>> response problems, but I want ln to be treated as log so that 
>> equivalent answers will be recognized, such as ln(x^n) and n*ln(x).
>>
>> Justin Gray | Senior Lecturer
>> Department of Mathematics | Simon Fraser University
>> 8888 University Drive, Burnaby | V5A 1S6 | Canada
>> Tel: +1 778.782.4237 | Fax: +1 778.782.4947 | Email: jgray@math.sfu.ca 
>> <mailto:jgray@math.sfu.ca>
>>
>>
> 

-- 
Peter Riegler
Fakultät Informatik
Ostfalia Hochschule für angewandte Wissenschaften
Fachhochschule Braunschweig/Wolfenbüttel
Salzdahlumer Str. 46/48
38302 Wolfenbüttel
Fon: ++49 5331 939 31540
http://public.rz.fh-wolfenbuettel.de/~riegler