format long
format compact

f = @(x) exp(x);

i = 1:10;
step = (1/2) .^ i;

threept = abs(hw08fprime3pt(f, 1, step) - exp(1));

hold on

plot(i, log2(threept), 'r');
plot(i, -2*i, 'r--');
plot(i, -i, 'g--');

hold off
