- #1

JasonPhysicist

- 13

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## Homework Statement

I'd like some help with 2 problems:

Show by using Demoivre's theorem and the geometric series formula that the sum of all n values of z^(1/n) is zero when n >=2.

Z is a complex number.

Use the geometric series formula and Demoivre's theorem to show that:

## Homework Equations

the geometric series formula:

Demoivre's theorem

## The Attempt at a Solution

For the first part,I've tried to make z^(1/n) = p so that p^n = z ,but I had no success showing that the sum equals zero...

For the second part I've made z= cos(theta) + i sin(theta) and I've obtained the left part of the formula,but I can't get the right part...

I'd appreciate any help,because I don't seem to be going anywhere.

Thank you in advance!

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