Let be an infinite complex geometric series such that and . Find the sum of all possible sums of this series.
Solution
Clearly, the possible common ratios are the 2013 roots of the equation . We want the sum of the values of , so we consider the polynomial whose roots are . It is easy to see that , so it follows that the are the roots of the polynomial equation . The leading coefficient of this polynomial is , and it follows easily from the Binomial Theorem that the next coefficient is 2013, so our answer is, by Vieta's Formulae,
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