Search For :

in:

All Sections 1. General Commands 2. System Calls 3. Subroutines 4. Special Files 5. File Formats 6. Games and Demos 7. Macros and Conventions 8. Maintenence Commands

 

NAME

acos, acosf, acosl - arc cosine function  

SYNOPSIS

#include <math.h>

double acos(double x);
float acosf(float x);
long double acosl(long double x);

 

DESCRIPTION

The acos() function calculates the arc cosine of x; that is the value whose cosine is x. If x falls outside the range -1 to 1, acos() fails and errno is set.  

RETURN VALUE

The acos() function returns the arc cosine in radians and the value is mathematically defined to be between 0 and PI (inclusive).  

ERRORS

EDOM

x is out of range.

 

CONFORMING TO

SVID 3, POSIX, BSD 4.3, ISO 9899. The float and long double variants are C99 requirements.  

SEE ALSO

asin(3), atan(3), atan2(3), cos(3), sin(3), tan(3)

---

 

Index

NAME

SYNOPSIS

DESCRIPTION

RETURN VALUE

ERRORS

CONFORMING TO

SEE ALSO