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. To use this function, compile either with the −Ae option or with the −Aa and −D_HPUX_SOURCE options. Otherwise, the compiler promotes the float argument to double, and the function returns incorrect results.

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, 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 zero and sets errno to [EDOM].

ERRORS

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

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

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