# Definition of cotan function [duplicate]

Possible Duplicate:
Define additional math operators to be typeset in roman

Is the cotan function defined somewhere? I cannot find it. It is defined as cotan(x)=cos(x)/sin(x). Should it be \newcommand{\cotan}{\mathrm{cotan}}? I'm suspecting somewhere a declareoperator command or something.

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For a function to calculate cotan=cos/sin, \usepackage{fp}... ;-) –  Bruno Le Floch Apr 9 '11 at 12:11