ACOSH(3) BSD Library Functions Manual ACOSH(3)

NAME
     aaccoosshh - inverse hyperbolic cosine function

SYNOPSIS
     ##iinncclluuddee <>

     double
     aaccoosshh(double x);

     long double
     aaccoosshhll(long double x);

     float
     aaccoosshhff(float x);

DESCRIPTION
     The aaccoosshh() function computes the principle value of the inverse hyper-
     bolic cosine of x.  The result is in the range [0, +infinity].

SSPPEECCIIAALL VVAALLUUEESS
     aaccoosshh(1) returns +0.

     aaccoosshh(x) returns a NAN and raises the "invalid" floating-point exception
     for x < 1.

     aaccoosshh(+infinity) returns +infinity.

SEE ALSO
     asinh(3), atanh(3), exp(3), math(3)

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

HISTORY     The aaccoosshh() and aaccoosshhff() function appeared in 4.3BSD.

4.3 Berkeley Distribution      November 15, 2002     4.3 Berkeley Distribution