I was reading several articles on Euler's identity, which is:(adsbygoogle = window.adsbygoogle || []).push({});

e^(i*x) = cos x + i*sin x

I understand what this formula describes: the unit circle on the complex plane, but I never really understood why e is there from a geometric point of view. So my question would be, what relationship does e have with the unit circle and why is it, as a result, a part of the formula?

Any links would also be greatly appreciated.

- Mark

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# Euler's formula - Question

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