git.r.bdr.sh - rbdr/dotfiles/blob

   1 'use strict';
   2
   3 var log = Math.log, sqrt = Math.sqrt;
   4
   5 module.exports = function (x) {
   6         if (isNaN(x)) return NaN;
   7         x = Number(x);
   8         if (x < 1) return NaN;
   9         if (x === 1) return 0;
  10         if (x === Infinity) return x;
  11         return log(x + sqrt(x * x - 1));
  12 };