tan(3) — Linux manual page

tan(3)                  Library Functions Manual                  tan(3)

NAME

       tan, tanf, tanl - tangent function

LIBRARY

       Math library (libm, -lm)

SYNOPSIS

       #include <math.h>

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

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

       tanf(), tanl():
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
               || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION

       These functions return 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.

ATTRIBUTES

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌─────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                           │ Attribute     │ Value   │
       ├─────────────────────────────────────┼───────────────┼─────────┤
       │ tan(), tanf(), tanl()               │ Thread safety │ MT-Safe │
       └─────────────────────────────────────┴───────────────┴─────────┘

STANDARDS

       C11, POSIX.1-2008.

HISTORY

       C99, POSIX.1-2001.

       The variant returning double also conforms to SVr4, 4.3BSD, C89.

BUGS

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

SEE ALSO

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

COLOPHON

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Linux man-pages 6.9.1          2024-05-02                         tan(3)

Pages that refer to this page: acos(3), asin(3), atan2(3), atan(3), cos(3), sin(3), sincos(3)

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