Wolfram Research
Wolfram Math World: Tangent
Graphs of the tangent function, both 2-dimensional and 3-dimensional. Higher level mathematics applications given including the hyperbolic tangent function, important relevant identities, the Macluarin series for the tangent function,...
Interactive Mathematics
Interactive Mathematics: Graphs of Tan, Cot, Sec, & Csc
Several examples are presented that demonstrate how to graph the tan, cot, sec, and csc functions.