one_over_e = exp(-1);
n = 1;
approx = (1 - 1/n)^n;
while abs(one_over_e - approx) >= 1.e-4
    n = n+1;
    approx = (1 - 1/n)^n;
end
fprintf('Acutal value: %8.5f ; approx value %7.4f ; n %i \n',one_over_e,approx,n)