code: function(point, f, fp) { 
          var maxiter = 200,
              iter = 0;
          //first try the point itself. If it's zero viola. We're done
          var x0 = point, x;
          do {
              var fx0 = f(x0); //store the result of the function
              //if the value is zero then we're done because 0 - (0/d f(x0)) = 0
              if(x0 === 0 && fx0 === 0) {
                  x = 0;
                  break;
              }
              iter++;
              if(iter > maxiter)
                  return; //naximum iterations reached
  
              x = x0 - fx0/fp(x0);
              var e = Math.abs(x - x0);
              x0 = x;
          }
          while(e > Number.EPSILON)
  
          return x;
      }
docs: Newton's iteration