ACOS(3)                  BSD Library Functions Manual                  ACOS(3)

NAME
     acos -- arc cosine function

SYNOPSIS
     ##include <>

     double
     acos(double x);

     long double
     acosl(long double x);

     float
     acosf(float x);

DESCRIPTION
     The acos() function computes the principle value of the arc cosine of x.
     The result is 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)

STANDARDS
     The acos() function conforms to ISO/IEC 9899:1999(E).

BSD                            November 14, 2002                           BSD