Finding \sum_{n=1}^{\infty} (-1)^n/n - Homework Help

Thread starter seanhbailey
Start date Feb 1, 2010
Tags

Alternating series Series

Feb 1, 2010

seanhbailey

Homework Statement

What is \sum_{n=1}^{\infty} (-1)^n/n

Homework Equations

The Attempt at a Solution

I know that the alternating series \sum_{n=1}^{\infty} (-1)^{n-1}/n converges to ln(2), but I am not sure how to find this series.

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Feb 1, 2010

Bohrok

(-1)^n-1 = (-1)ⁿ(-1)^-1 = -1*(-1)ⁿ
then you can take the constant -1 outside the sum.

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