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  • Perplex
    IB Math AAHL
    /
    Sequences & Series
    /

    Problem Bank

    [Maximum mark: 8]

    Consider the polynomial ​P(x)=27x4+245​x3+ax2+bx+34​, where ​a,b∈R.

    The roots of the equation ​P(x)=0​ are consecutive terms in a geometric sequence with first term ​u1​​ and common ratio ​r, where ​u1​<0​ and ​∣r∣<1.

    1. Give two expressions for ​u1​​ in terms of ​r.

      [5]
    2. Hence find the values of ​u1​​ and ​r​

      [3]

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