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20
Math Prize 2010 Problem 20
Math Prize 2010 Problem 20
Source:
November 14, 2010
trigonometry
algebra
polynomial
Vieta
function
ratio
complex numbers
Problem Statement
What is the value of the sum
∑
z
1
∣
1
−
z
∣
2
,
\sum_z \frac{1}{{\left|1 - z\right|}^2} \, ,
z
∑
∣
1
−
z
∣
2
1
,
where
z
z
z
ranges over all 7 solutions (real and nonreal) of the equation
z
7
=
−
1
z^7 = -1
z
7
=
−
1
?
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