TAN(3)                                              Linux Programmer's Manual                                             TAN(3)



NAME
       tan, tanf, tanl - tangent function

SYNOPSIS
       #include <math.h>

       double tan(double x);
       float tanf(float x);
       long double tanl(long double x);

       Link with -lm.

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       tanf(), tanl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or cc -std=c99

DESCRIPTION
       The tan() function returns the tangent of x, where x is given in radians.

RETURN VALUE
       On success, these functions return the tangent of x.

       If x is a NaN, a NaN is returned.

       If x is positive infinity or negative infinity, a domain error occurs, and a NaN is returned.

       If  the  correct result would overflow, a range error occurs, and the functions return HUGE_VAL, HUGE_VALF, or HUGE_VALL,
       respectively, with the mathematically correct sign.

ERRORS
       See math_error(7) for information on how to determine whether an error has occurred when calling these functions.

       The following errors can occur:

       Domain error: x is an infinity
              An invalid floating-point exception (FE_INVALID) is raised.

       Range error: result overflow
              An overflow floating-point exception (FE_OVERFLOW) is raised.

       These functions do not set errno.

CONFORMING TO
       C99, POSIX.1-2001.  The variant returning double also conforms to SVr4, 4.3BSD, C89.

SEE ALSO
       acos(3), asin(3), atan(3), atan2(3), cos(3), ctan(3), sin(3)

COLOPHON
       This page is part of release 3.25 of the Linux man-pages project.  A description of the project,  and  information  about
       reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.



                                                           2008-08-05                                                     TAN(3)