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Section 5.6 Exercises

1

Suppose that \(f\) has a fixed point at \(z_0\text{.}\) Show that the function \(g\) obtained by conjugating \(f\) with the function \(\varphi(z)=z+z_0\) has a fixed point at zero. In addition, show that the conjugation preserves the nature of the fixed point as attractive, super-attractive, repulsive, or neutral.

2

Suppose that

\begin{equation*} f(z) = a_m z^m + a_{m+1} z^{m+1}+\cdots, \end{equation*}

so that \(f\) has a super-attractive fixed point of order \(m\) at zero. Show that the function \(g\) obtained by conjugating \(f\) with the function \(\varphi(z)=a_m^{1/(m-1)}z\) conjugates \(f\) to a function \(g\) of the form

\begin{equation*} g(z) = z^m + a_{m+1}' z^{m+1}+\cdots \end{equation*}