cot(x), sec(x) and csc(x) trigonometric functions

[Former user]

Originally reported on Google Code with ID 49

Along with sin(x), cos(x) and tan(x), we should provide the specified
trigonometric functions stated in the title of this issue, according to:

http://en.wikipedia.org/wiki/Trigonometric_function
http://mathworld.wolfram.com/topics/TrigonometricFunctions.html

Reported by helder.pereira.correia on 2007-06-13 23:24:34

[Former user]

``` Implemented in trunk, will be available for 0.8. Marking as fixed. ```

Reported by `helder.pereira.correia` on 2007-06-13 23:25:16 - Status changed: `Fixed`