HP-UX Reference (11i v2 07/12) - 3 Library Functions A-M (vol 6)

c
cacos(3M) cacos(3M)
(Itanium(R)-based System Only)
NAME
cacos(), cacosf( ), cacosl(), cacosw( ), cacosq() - complex arccosine functions
SYNOPSIS
#include <complex.h>
double complex cacos(double complex z);
float complex cacosf(float complex z);
long double complex cacosl(long double complex z);
extended complex cacosw(extended complex z);
quad complex cacosq(quad complex z);
DESCRIPTION
These functions are available only for Itanium-based systems.
cacos() returns the complex arccosine of z, in the range of a strip mathematically unbounded along the
imaginary axis and in the interval [0,Pi] along the real axis.
Branch cuts are outside the interval [-1,+1] along the real axis.
cacosf() is a float complex version of cacos(); it takes a float complex argument and
returns a
float complex result.
cacosl() is a long double complex cacos(); it takes a long double complex argument and
returns a long double complex result.
cacosw() is an extended complex version of cacos(); it takes an extended complex argu-
ment and returns an
extended complex result.
cacosq() is equivalent to cacosl() on HP-UX systems.
USAGE
To use these functions, compile with the default -Ae option. To use cacosw() or
cacosq(), compile
with the
-fpwidetypes option. Make sure your program includes <complex.h> , and link in the
math library by specifying -lm on the compiler or linker command line.
RETURN VALUE
cacos(conj(z)) = conj(cacos(z))
cacos(±0+i0) returns Pi/2-i0.
cacos(±0+iNaN) returns Pi/2+iNaN.
cacos(x+iInf) returns Pi/2-iInf, for finite x.
cacos(x+iNaN) returns NaN+iNaN and optionally raises the invalid floating-point exception, for nonzero
finite x.
cacos(-Inf+iy) returns Pi-iInf, for positive-signed finite y.
cacos(+Inf+iy) returns +0-iInf, for positive-signed finite y.
cacos(-Inf+iInf) returns 3Pi/4-iInf.
cacos(+Inf+iInf) returns Pi/4-iInf.
cacos(±Inf+iNaN) returns NaN±iInf (where the sign of the imaginary part of the result is unspecified).
cacos(NaN+iy) returns NaN+iNaN and optionally raises the invalid floating-point exception, for finite y.
cacos(NaN+iInf) returns NaN-iInf.
cacos(NaN+iNaN) returns NaN+iNaN.
ERRORS
No errors are defined.
SEE ALSO
acos(3M), ccos(3M), complex(5).
148 Hewlett-Packard Company − 1 − HP-UX 11i Version 2: December 2007 Update