Find the points at which
is continuous and at which
is continuous.
Since
and ,
are continuous everywhere we know (by Theorem 3.2) that
is continuous everywhere
is not zero. We proved in this exercise (Section 2.8, #1 (b) of Apostol) that
Thus, is continuous for
Similarly,
and by Theorem 3.2 we then have is continuous everywhere that
is not zero. We proved in the same exercise (Section 2.8, #1(a) of Apostol) that
Hence, is continuous for