acosh(p1)
  public
  
    
    
Computes the inverse hyperbolic cosine of x.
Domain: [1, INFINITY)
Codomain: [0, INFINITY)
Math.acosh(1) 
   
  
    Show source    
    
      static VALUE
math_acosh(VALUE unused_obj, VALUE x)
{
    double d;
    d = Get_Double(x);
    /* check for domain error */
    if (d < 1.0) domain_error("acosh");
    return DBL2NUM(acosh(d));
}