ACOS(3) BSD Library Functions Manual ACOS(3)
NAME
acos -- arc cosine function
SYNOPSIS
#include <math.h>
double
acos(double x);
DESCRIPTION
The acos() function computes the principal value of the arc cosine of x in the range [0, pi].
SPECIAL VALUES
acos(1) returns +0.
acos(x) returns a NAN and raises the "invalid" floating-point exception for |x| > 1.
SEE ALSO
sin(3), cos(3), tan(3), asin(3), atan(3), atan2(3), sinh(3), cosh(3), tanh(3), math(3), matherr(3)
STANDARDS
The acos() function conforms to ISO/IEC 9899:1999(E).
BSD
November 14, 2002 BSD
