Adding remote computational capabilities to Dynamic Geometry Systems

A Dynamic Geometry System (DGS) is a computer application that allows the exact drawing and dynamic manipulation of geometric constructions. DGS have been the paradigm of new technologies applied to Math education, but some authors have claimed that some symbolic capabilities should be added to this systems. We present an example of communication between the commercial DGS Cabri, The Geometer's Sketchpad and Cinderella and two Computer Algebra Systems (CAS), Mathematica and CoCoA. The tool is a web application designed to symbolically process locus, proof and discovery tasks on geometric diagrams. Named LAD (Locus-Assertion-Discovery), it is a remote add-on for the three DGS. LAD is a prototype oriented to research users. We also describe LADucation, a one-click educational version of LAD. By just uploading the file generated by the considered DGS, graphs and equations of geometric loci are computed.