Rouche's Theorem: Find Zeros of f(z)=z^9-2z^6+z^2-8z-2 Inside Unit Circle

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Homework Statement


Find the number of zeros of the folowing polynomial lying inside the unit circle,
f(z)= z^9 - 2z^6 + z^2 - 8z - 2



The Attempt at a Solution


Rouche's Theorem says if f and g differentiable which contains a simple loop s and all points inside s.
if |f(z)-g(z)|<|f(z)| for all z=s(t)
then f and g have same zeros inside s.

which g(z) should I choose, -2z^6, or z^2 or -8z
how can I determine?
 
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Try, -8z. In general, try the term with the highest coefficient...
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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