### Author Topic: Q5: TUT 0201  (Read 1356 times)

#### Ziyi Wang

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##### Q5: TUT 0201
« on: March 08, 2020, 06:46:48 PM »
Question: Give the order of each of zeros of the given function.
$$Log(1-z), |z|<1$$
Let $f(z)=Log(1-z), |z|<1$. Let $f(z_0)=0$. Then, we get that $z_0=0$.
Since, $f'(z) = \frac{-1}{1-z}$, we know that $f'(z_0) = -1 \neq 0$.
Therefore, the order of $z_0 = 0$ of the given function is $1$.