# [LON-CAPA-users] Sketching Graphs

Gerd Kortemeyer korte at lite.msu.edu
Fri Feb 3 19:01:37 EST 2012

```Hi,

On Feb 3, 2012, at 4:20 PM, Seema Ali wrote:

> How do you create a problem (through Geogebra) to get students to sketch a graph and mark it?

I am attaching an additional XML example, which uses "labels" - these are flexible boundaries, for example, it can get set to the value when another rule is not true anymore. The graduate student involved in the design of this is J. T. Laverty, laverty1 at msu.edu (cc'd here).

- Gerd.

<problem>
<script type="loncapa/perl">\$maxacc=&random(3,5,1);
\$maxbraketime=&random(6,10,2);
\$wait=&random(2,4,1);</script>
<startouttext />
At t=0 s, a car cruises at a constant positive velocity. Suddenly, a light switches to red. At t=\$maxbraketime s, the driver is maximum on the brake. The car then stops in front of the red light for over \$wait seconds. Eventually, it drives off, and then again cruises at a constant velocity. The car cannot accelerate with more than \$maxacc m/s<sup>2</sup>.<br />
Provide a graph of its acceleration as a function of time.<br /> <endouttext />
<functionplotresponse xaxisvisible="yes" xlabel="t [s]" gridvisible="yes" ylabel="a(t) [m/s^2]" id="11" xmax="30" yaxisvisible="yes" xmin="-4" ymin="-8" ymax="8" answerdisplay="0::\$maxbraketime-4,-7*(exp(-0.5*(x-\$maxbraketime)^2)-exp(-8)):\$maxbraketime-4:\$maxbraketime+4,0:\$maxbraketime+4:\$maxbraketime+5+\$wait,(\$maxacc-0.3)*(exp(-(x-(\$maxbraketime+7+\$wait))^2)-exp(-4)):\$maxbraketime+5+\$wait:\$maxbraketime+9+\$wait,0:\$maxbraketime+9+\$wait">
<functionplotelements>
<spline initx="-2" inity="0" index="A" order="8" scalex="28" />
</functionplotelements>
<functionplotruleset>
<functionplotrule relationship="eq" xinitiallabel="start" xfinallabel="brake" value="0" derivativeorder="0" percenterror="1" minimumlength="1" />
<functionplotrule relationship="eq" xinitial="0" value="0" derivativeorder="0" percenterror="1" />
<functionplotrule relationship="lt" xinitiallabel="brake" xfinallabel="stop" value="-0.1" derivativeorder="0" />
<functionplotrule relationship="eq" xinitial="\$maxbraketime" value="0" derivativeorder="1" percenterror="40" />
<functionplotrule relationship="eq" xinitiallabel="stop" xfinallabel="driveoff" value="0" derivativeorder="0" percenterror="1" minimumlength="\$wait" />
<functionplotrule relationship="gt" xinitiallabel="driveoff" xfinallabel="cruise" value="0.1" derivativeorder="0" />
<functionplotrule relationship="le" xinitiallabel="driveoff" xfinallabel="cruise" value="\$maxacc" derivativeorder="0" />
<functionplotrule relationship="eq" xinitiallabel="cruise" xfinallabel="end" value="0" derivativeorder="0" percenterror="1" minimumlength="1" />
</functionplotruleset>
</functionplotresponse>
</problem>
```