% MatLab function for part 1 of the question for the CSC 336 tutorial
% on 29 Sept. 2007.
%
% This function approximates e^x by summing the series
%      1 + x + x^2/2! + x^3/3! + ...
% from left to right until the value of the sum does not change.
%
%					K.R.J.    24 Sept. 2007

function y = exp1(x)
   
   sumold = 0;
   sum = 1;

   k = 0;
   term = 1;	% term will be x^k/k!  We increment each time around the
                % while look to avoid having to recompute x^k/k!

   while sumold ~= sum,
      sumold = sum;
      k = k+1;
      term = term * x / k;
      sum = sum + term;
   end

   y = sum;