- #1

- 39

- 0

## Homework Statement

1/2 + 2/4 + 3/8 + 4/16 + 5/32 + ...

## Homework Equations

## The Attempt at a Solution

The only headway I've made is that this is ∑ n/(2^n). how do I go about summing this?

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- Thread starter pyrosilver
- Start date

- #1

- 39

- 0

1/2 + 2/4 + 3/8 + 4/16 + 5/32 + ...

The only headway I've made is that this is ∑ n/(2^n). how do I go about summing this?

- #2

lanedance

Homework Helper

- 3,304

- 2

how about starting by adding up the first few terms and looking for a pattern with n terms

- #3

Dick

Science Advisor

Homework Helper

- 26,260

- 619

Define f(x)=x^n/2^n. If you find that then your sum just might be related to f'(x) at x=1.

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