Students can draw graphs in a coordinate system. This program is good for especially high school students. The program makes it very easy to visualize a function and paste it into another program. Students can do calculations on the functions.
G. Davis, and M. Mcgowen. proceedings of the Annual Meeting of the 26th Annual Meeting of the International Group for the Psychology of Mathematics Education (PME), 2, page 273-280. Norwich, UK, University of Norwich, (July 2002)
M. Carlson, M. Oehrtman, and P. Thompson. Making the Connection: Research and Practice in Undergraduate Mathematics, Mathematical Association of America, Washington, DC, (2008)
L. Saldanha, and P. Thompson. Proceedings of the Annual Meeting of the Psychology of Mathematics Education - North America, Raleigh, NC, North Carolina State University, (1998)