From: Descarta2D on
The Mathematica add-on package, Descarta2D, has been certified to be
compatible with Mathematica Version 7 (previously certified for
Versions 3-6). The entire textbook "Exploring Analytic Geometry with
Mathematica" (including the user manual for Descarta2D) is available
for free viewing and download at www.Descarta2D.com (both PDF and on-
line versions, 865 pages, ~3Mb, are available).

The corresponding Descarta2D Mathematica notebooks are available for
purchase at the same web site (the notebooks are not required to read/
study the textbook, but they are needed to re-run the sample problems
or to use Descarta2D for applications beyond the samples).