tan - Man Page

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).

InterfaceAttributeValue
tan(), tanf(), tanl()Thread safetyMT-Safe

Standards

C99, POSIX.1-2001, POSIX.1-2008.

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.

See Also

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

Referenced By

acos(3), asin(3), atan(3), atan2(3), cos(3), sin(3), sincos(3).

The man pages tanf(3) and tanl(3) are aliases of tan(3).

2022-10-09 Linux man-pages 6.01