This module is a classical exercise of plane geometry. The server generates a random plane curve (cartesian, parametrized or polar according to the initial choice), and present its equation as well as a drawing. And you will be asked to compute the equation of the tangent or normal line of the curve at a given point.
Please take note that WIMS pages are interactively generated; they are not ordinary HTML files. They must be used interactively ONLINE. It is useless for you to gather them through a robot program.