[LON-CAPA-users] Having an equation or a range as a response

[Gerd Kortemeyer]

Hi,

On Jan 19, 2012, at 8:39 PM, Seema Ali wrote:

> An example would be:
>  
> State the equation for the asymptote for the graph y=10^(x+7)+8.
> Answer:  [answer box]
>  
> I would like the student to enter the entire equation into the answer box.

So that would be x=7 or y=8, correct?

<problem>
<script type="loncapa/perl">$a=&random(3,8,1);
$b=$a+&random(2,5,1);
$sample="x=$a or y=$b would be correct";
</script>

<startouttext />
Given an equation for an asymptote of <m eval="on">$y=10^{x+$a}+$b$</m>.
<endouttext />

<customresponse answerdisplay="$sample">
<answer type="loncapa/perl">

# Get left and right side of equation
($left,$right)=split(/\s*\=\s*/,$submission);

# We want something on both sides of the equation
unless (($left=~/\w/) && ($right=~/\w/)) { return 'BAD_FORMULA'; }

# Use computer algebra system to see if it agrees to one of our desired equations
if (&cas('maxima',"($left)-($right)-(x-$a)") eq '0') { return 'EXACT_ANS'; }
if (&cas('maxima',"($left)-($right)-(y-$b)") eq '0') { return 'EXACT_ANS'; }

# Too bad ...
return 'INCORRECT';
</answer>
    <textline readonly="no" />
</customresponse>

</problem>

Let me know if that does the trick.

- Gerd.