.\" Copyright (c) 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" %sccs.include.redist.man% .\" .\" @(#)tan.3 8.1 (Berkeley) 06/04/93 .\" .Dd .Dt TAN 3 .Os .Sh NAME .Nm tan .Nd tangent function .Sh SYNOPSIS .Fd #include .Ft double .Fn tan "double x" .Sh DESCRIPTION The .Fn tan function computes the tangent of .Fa x (measured in radians). A large magnitude argument may yield a result with little or no significance. For a discussion of error due to roundoff, see .Xr math 3 . .Sh RETURN VALUES The .Fn tan function returns the tangent value. .Sh SEE ALSO .Xr acos 3 , .Xr asin 3 , .Xr atan 3 , .Xr atan2 3 , .Xr cos 3 , .Xr cosh 3 , .Xr sin 3 , .Xr sinh 3 , .Xr tanh 3 , .Xr math 3 , .Sh STANDARDS The .Fn tan function conforms to .St -ansiC .