Suppose that is analytic at .
Prove that a necessary and sufficient condition that is a zero of order is that can be written as
where is analytic and nonzero at .
The proof seems intuition, but I don't know where to start. Thank you.
Suppose that is analytic at .
Prove that a necessary and sufficient condition that is a zero of order is that can be written as
where is analytic and nonzero at .
The proof seems intuition, but I don't know where to start. Thank you.