- Why we cannot use inscribed polyhedrons to approximate the area of a curved surface [Cou2, vol.2, p.421, l.-10-p.422,
l.16; p.540, l.-14-p.542, l.12].

- The indeterminate form ¥×0: Finding the sum of an infinite number of terms, where each term is
infinitesimal.

Example. lim_{n ® + ¥}(1 - 1/(2n) + 1/(3n^{2}) - …) [Wat1, p.584, l.17].

We may regard the series as the power series of the analytic function

f (t) = [log (1+t)]/t.

Then lim_{t®0}f (t) = f (0) since an analytic function is continuous.