_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
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

errno
is set to
EDOM
(but see BUGS).
An invalid floating-point exception
(FE_INVALID)
is raised.

Range error: result overflow

An overflow floating-point exception
(FE_OVERFLOW)
is raised.

CONFORMING TO

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

BUGS

Before version 2.10, the glibc implementation did not set
errno
to
EDOM
when a domain error occurred.

This page is part of release 3.27 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/.