If you’ve got a desktop or laptop Mac, GeoGebra 5 is now available in the Mac App Store. (A Windows version should be available soon too).
GeoGebra 5 adds 3D graphing capabilities. Earlier in the course we had looked at a question that had a geometric interpretation. Have a look at the new version of GeoGebra and see if you can produce a visual representation of the problem we had solved.