HP-UX Reference (11i v2 04/09) - 3 Library Functions A-M (vol 6)

acosd(3M) acosd(3M)

NAME

acosd( ), acosdf( ), acosdl( ), acosdw( ), acosdq( ) - degree-valued arccosine functions

SYNOPSIS

#include <math.h>

double acosd(double x);

float acosdf(float x);

Itanium(R)-based System Only

long double acosdl(long double x);

extended acosdw(extended x);

quad acosdq(quad x);

DESCRIPTION

acosd() returns the degree-valued arccosine of x, in the range 0 to 180.

acosdf() is a float version of acosd(); it takes a

float argument and returns a float result.

Itanium-based System Only

acosdl() is a long double version of acosd(); it takes a long double argument and returns a

long double result.

acosdw() is an extended version of acosd(); it takes an extended argument and returns an

extended result.

acosdq() is equivalent to acosdl() on HPUX systems.

USAGE

To use these functions, compile either with the default

-Ae option or with the -Aa

and

-D_HPUX_SOURCE options.

To use (for Itanium-based systems)

acosdw() or acosdq(), compile also with the -fpwidetypes

option.

To use any of these functions, make sure your program includes

<math.h>, and link in the math library

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

For more information, see the HP-UX Floating-Point Guide.

RETURN VALUE

acosd() returns +0.

If the magnitude of x is greater than one,

acosd() returns NaN and raises the invalid exception.

If x is NaN,

acosd() returns NaN.

ERRORS

If the magnitude of x is greater than one,

acosd() sets errno to [EDOM].

Itanium-based System Only

HP-UX libm functions on IPF do not set

errno by default. For errno setting, compile with the +Olib-

merrno option.