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MathNet 2009-part-02 — 175 problems (EN–VI) Question 75

Math Olympiad Vault · MathNet 2009-part-02 — 175 problems (EN–VI)

Question 75

Let $x$ be the smaller of the two solutions of the equation $x^{2}-4x+2=0$. What are the first three digits after the decimal point in the (base 10) writing of the number
$$
x+x^{2}+x^{3}+\cdots+x^{2009} ?
$$