- #1

- 60

- 0

## e^{i\theta} = cos{\theta} + isin{\theta} ##

Set ##\theta = 2\pi ##

## e^{2\pi i} = cos{2\pi} + isin{2\pi} ##

## e^{2\pi i} = 1 ##

Take the natural log:

## ln{e^{2\pi i}} = ln{1} ##

## 2\pi i = 0 ##

## i = sqrt{-1} = 0 ##

## -1 = 0 ##

I think the problem was in using the natural log up there, but I'm not positive.