Manual Pages  — TANPI

tanpi, tanpif, tanpil – half-cycle tangent functions

LIBRARY SYNOPSIS DESCRIPTION RETURN VALUES SPECIAL VALUES SEE ALSO AUTHORS STANDARDS

Math Library (libm, -lm)

#include <math.h>

double
tanpi(double x);

float
tanpif(float x);

long double
tanpil(long double x);

The tanpi(), tanpif(), and tanpil() functions compute the tangent of π µ x and measure angles in half-cycles.

The tanpi(), tanpif(), and tanpil() functions returns tan(π µ x). If |x| ≥ 2^(p - 1) where p is the floating-point precision of x, then the returned value is ±0 and it has no significance.

	tanpi(±0) returns ±0.
	tanpi(±n) returns ±0 for positive integers n.
	tanpi(±n/2) returns NaN for n > 0 and raises an FE_INVALID exception.
	tanpi(±∞) return an NaN and raises an FE_INVALID exception.
	tanpi(NaN) return an NaN and raises an FE_INVALID exception.

The half-cycle trignometric functions were written by Steven G. Kargl <Mt kargl@FreeBSD.org>.

These functions conform to IEEE Std 754&#174;-2008 , dqIEEE Standard for Floating-Point Arithmeticdq and to ISO/IEC TS 18661-4 , dqInformation technology &#151; Programming languages, their environments, and system software interfaces &#151; Floating-point extensions for Cdq &#151; Part 4: Supplementary functions.