Content-type: text/html Man page of asinh

# asinh

Section: C Library Functions (3)

## NAME

asinh, acosh, atanh - Compute inverse hyperbolic functions

## LIBRARY

Math Library (libm.a)

## SYNOPSIS

#include <math.h>

double asinh (double x); float asinhf (float x); double acosh (double x); float acoshf (float x); double atanh (double x); float atanhf (float x);

## STANDARDS

Interfaces documented on this reference page conform to industry standards as follows:

asinh(): XPG4-UNIX

acosh(): XPG4-UNIX

atanh(): XPG4-UNIX

## DESCRIPTION

The asinh() and asinhf() functions return the hyperbolic arc sine of x, in the range [-infinity, +infinity] where asinh(x) = ln(x + sqrt(x**2 + 1)). The asinh() function is the reverse function of sinh() where asinh(sinh(x)) = x.

The acosh() and acoshf() functions return the hyperbolic arc cosine of x, in the range [1, +infinity] where acosh(x) = ln(x + sqrt(x**2 - 1)). The acosh() function is the reverse function of cosh() where acosh(cosh(x)) = x.

The atanh() and atanhf() functions return the hyperbolic arc tangent of x, in the range (-1, 1). The atanh() function is the reverse function of tanh() where atanh(tanh(x)) = x.

The following table describes function behavior in response to exceptional arguments:

 Function Exceptional Argument Routine Behavior asinh() None N/A asinhf() None N/A acosh() x<1 Invalid argument acoshf() x<1 Invalid argument atanh() x>1 or x=1 Invalid argument atanhf() x>1 or x=1 Invalid argument
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## Index

NAME
LIBRARY
SYNOPSIS
STANDARDS
DESCRIPTION

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Time: 02:41:06 GMT, October 02, 2010