Digital

NAME

asinh, acosh, atanh − Computes inverse hyperbolic functions

LIBRARY

Math Library (libm.a)

SYNOPSIS

#include <math.h>

double asinh (
  double x );
double atanh (
  double x );
double acosh (
  double x );

PARAMETERS

xSpecifies some double value. 

DESCRIPTION

The asinh() function returns the hyperbolic arc sine of x, in the range -infinity to +infinity.  The acosh() function returns the hyperbolic arc cosine of x, in the range 1 to +infinity.  The atanh() function returns the hyperbolic arc tangent of x, in the range -infinity to +infinity. 

NOTES

Errors due to roundoff and other factors: These functions inherit much of their error from log1p described in exp(3). 

RETURN VALUES

Upon successful completion, the asinh(), acosh(), and atanh() functions return the hyperbolic arc sine, hyperbolic arc cosine, and hyperbolic arc tangent of x.  Otherwise, acosh() function returns a NaNQ if x < 1, and the atanh() function returns a NaNQ if x > 1. 

RELATED INFORMATION

Functions: exp(3), sinh(3), math(3)