NAME    [Toc]    [Back]

     acosh, acoshf - inverse hyperbolic cosine function

LIBRARY    [Toc]    [Back]

     Math Library (libm, -lm)

SYNOPSIS    [Toc]    [Back]

     #include <math.h>

     double
     acosh(double x);

     float
     acoshf(float x);

DESCRIPTION    [Toc]    [Back]

     The acosh() and acoshf() functions compute the inverse hyperbolic cosine
     of the real argument x.

RETURN VALUES    [Toc]    [Back]

     If x is less than one, acosh(x) and acoshf(x) return NaN and set the
     global variable errno to EDOM.

SEE ALSO    [Toc]    [Back]

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

HISTORY    [Toc]    [Back]

     The acosh() function appeared in 4.3BSD.

BSD                               May 6, 1991                              BSD