HP-UX Reference (11i v1 05/09) - 3 Library Functions A-M (vol 6)

acosd(3M) acosd(3M)

NAME

acosd(), acosdf() - degree-valued arccosine functions

SYNOPSIS

#include <math.h>

double acosd(double x);

float acosdf(float x);

DESCRIPTION

acosd() is a degree-valued version of the

acos() function. It returns the 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.

acosd() and acosdf() are not speciﬁed by any standard, but

acosdf() is named in accordance with

the conventions speciﬁed in the "Future Library Directions" section of the ANSI C standard.

To use these functions, compile either with the default

-Ae option or with the -Aa and

-D_HPUX_SOURCE options. Make sure your program includes <

math.h>. Link in the math library by

specifying

-lm on the compiler or linker command line.

RETURN VALUE

If x is NaN, acosd() returns NaN.

If the magnitude of x is greater than one, acosd() returns NaN and sets errno to [EDOM].

ERRORS

acosd() fails, errno is set to the following value.

[EDOM] The magnitude of x is greater than one.