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    (Original post by Simplicity)
    No that is wrong. When did it say n=0. I'm pretty sure it starts at n=1 and goes on.

    Again, your wrong it works fine without replacing n with n-1.
    It didnt say it starts with anything, even if it starts with 1 it still doesnt give you the series does it?

    (Original post by ShortRef)
    Can we please go back and actually discuss if the question is right or not.

    "Sum the series 1 + 4x + 7x² + 10x³ + ... + (3N - 2)x^N."

    so the general term is (3N - 2)x^N

    Putting N = 0 gives -2
    Putting N = 1 gives (3 - 2)x^1 = x
    Putting N = 2 gives (6 - 2)x^2 = 4x^2
    Putting N = 2 gives (9 - 2)x^3 = 7x^3

    So the series has to be (3n - 2)x^(n-1)
    N=3. Typo. n=0 gives 1

    Okay that looks correct.
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Updated: August 6, 2009


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