# Calculus

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Show that the following series is absolutely convergent:

Summation from 1 to infinity:

[(-1)^n * (n+1) * 3^n]/ [2^(2n+1)]

I've done the ratio test and replaced n in this series with n+1. I get 3/4 in the end, which is less than 1, which confirms that the series is abs. convergent, but when I put it in the calculator the answer is 0. Can someone do this problem and show me where I might have made a mistake?

Thank you

• Calculus -

ratio test:
k(n)/k(n+1)

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