Math.acosh(x)    → float

Computes the inverse hyperbolic cosine of x.

Source Code

/*
*  call-seq:
*     Math.acosh(x)    => float
*  
*  Computes the inverse hyperbolic cosine of <i>x</i>.
*/

static VALUE
math_acosh(obj, x)
   VALUE obj, x;
{
   double d;

   Need_Float(x);
   errno = 0;
   d = acosh(RFLOAT(x)->value);
   domain_check(d, "acosh");
   return rb_float_new(d);
}