CFLib.org – Common Function Library Project

Description:
Returns the inverse hyberbolic cosine of a value. All angles are expressed in radians.

Return Values:
Returns an angle in radians.

Example:

<CFSET x=1.5>
  <CFOUTPUT>
  Given x=1.5<BR>
  The Acosh of #x# is: #Acosh(x)# radians
  </CFOUTPUT>

Parameters:

Full UDF Source:

<cfscript>
/**
 * Returns the inverse hyperbolic cosine of a value.
 * 
 * @param x 	 Any real number. 
 * @return Returns an angle in radians. 
 * @author Joel Cox (&#106;&#108;&#99;&#111;&#120;&#64;&#103;&#111;&#111;&#100;&#121;&#101;&#97;&#114;&#46;&#99;&#111;&#109;) 
 * @version 1, November 29, 2001 
 */
function Acosh(x)
{
  Var RetVal = 0;
  if (x LTE 1.0) 
    RetVal = 0.0;
  else if (x GTE 1.0e10) 
    RetVal = Log(2) + Log(x);
  else
    RetVal = Log(x + Sqr((x - 1.0) * (x + 1.0)));
  Return(RetVal);
}
</cfscript>