HP-UX Reference (11i v2 03/08) - 3 Library Functions A-M (vol 6)

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casin(3M) casin(3M)

(Itanium(R)-based System Only)

NAME

casin( ), casinf( ), casinl( ), casinw( ), casinq( ) - complex arcsine functions

SYNOPSIS

#include <complex.h>

double complex casin(double complex z);

float complex casinf(float complex z);

long double complex casinl(long double complex z);

extended complex casinw(extended complex z);

quad complex casinq(quad complex z);

DESCRIPTION

These functions are available only for Itanium-based systems.

casin() returns the complex arcsine of z, in the range of a strip mathematically unbounded along the

imaginary axis and in the interval [-Pi/2,+Pi/2] along the real axis. Branch cuts are outside the interval

[-1,+1] along the real axis.

casinf() is a float complex version of casin(); it takes a float complex argument and

returns a float complex result.

casinl() is a long double complex version of casin(); it takes a long double complex argu-

ment and returns a long double complex result.

casinw() is an extended complex version of casin(); it takes an extended complex argument

and returns an extended complex result.

casinq() is equivalent to casinl() on HP-UX systems.

USAGE

To use these functions, compile with the default

-Ae option. To use casinw() or

casinq(), compile

with the

-fpwidetypes option. Make sure your program includes <complex.h>. Link in the math

library by specifying -lm on the compiler or linker command line.

RETURN VALUE

casin(conj(z)) = conj(casin(z)) and casinh is an odd function.

casin(+0+i0) returns 0+i0.

casin(Inf+iy) returns Pi/2+iInf for positive-signed ﬁnite y.

casin(NaN+iy) returns NaN+iNaN and may raise the invalid exception for ﬁnite y.

casin(x+iInf) returns +0+iInf for positive-signed ﬁnite x.

casin(+Inf+iInf) returns Pi/4+iInf.

casin(NaN+iInf) returns NaN+iInf.

casin(+0+iNaN) returns +0+iNaN.

casin(x+iNaN) returns NaN+iNaN and may raise the invalid exception for ﬁnite nonzero x.

casin(Inf+iNaN) returns NaN±iInf (where the sign of the imaginary part of the result is unspeciﬁed).

casin(NaN+iNaN) returns NaN+iNaN.

ERRORS

No errors are deﬁned.