Tribblix: manual page: tan.3m

TAN(3M) Mathematical Library Functions TAN(3M)

NAME

tan, tanf, tanl - tangent function

SYNOPSIS

c99 [ flag... ] file... -lm [ library... ]
#include <math.h>

double tan(double x);

float tanf(float x);

long double tanl(long double x);

DESCRIPTION

These functions compute the tangent of their argument x, measured in
radians.

RETURN VALUES

Upon successful completion, these functions return the tangent of x.

If x is NaN, a NaN is returned.

If x is +-0, x is returned.

If x is +-Inf, a domain error occurs and a NaN is returned.

ERRORS

These functions will fail if:

Domain Error
The value of x is +-Inf.

If the integer expression (math_errhandling &
MATH_ERREXCEPT) is non-zero, the invalid floating-
point exception is raised.

USAGE

There are no known floating-point representations such that for a
normal argument, tan(x) is either overflow or underflow.

An application wanting to check for exceptions should call
feclearexcept(FE_ALL_EXCEPT) before calling these functions. On
return, if fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW |
FE_UNDERFLOW) is non-zero, an exception has been raised. An
application should either examine the return value or check the
floating point exception flags to detect exceptions.

ATTRIBUTES