acos(3)
NAME
acos, acosf -- arc cosine functions
LIBRARY
Math Library (libm, -lm)
SYNOPSIS
#include <math.h> double acos(double x); float acosf(float x);
DESCRIPTION
The acos() and the acosf() functions compute the principal value of the arc cosine of x. A domain error occurs for arguments not in the range [-1, +1]. For a discussion of error due to roundoff, see math(3).
RETURN VALUES
The acos() and the acosf() functions return the arc cosine in the range [0, pi] radians. If: |x| > 1, acos(x) raises an invalid exception and returns an NaN.
SEE ALSO
asin(3), atan(3), atan2(3), cos(3), cosh(3), fenv(3), math(3), sin(3), sinh(3), tan(3), tanh(3)
STANDARDS
The acos() function conforms to ISO/IEC 9899:1990 (``ISO C90''). FreeBSD 5.4 January 14, 2005 FreeBSD 5.4
SPONSORED LINKS
Man(1) output converted with man2html , sed , awk