e^-it as t approaches infinity

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How do I evaluate $$ \lim_{t\rightarrow \infty } e^{-it}$$

I feel like it should be 0, but I'm not sure if the $i$ changes things.

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There are 3 best solutions below

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On

Hint:

$$e^{iat}=\cos at + i \sin at$$

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Here is how you can interpret this limit using argand plane. The solution region is a square and there is no definite value for this limitargand plane limit of e^-it solution

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$e^{it}=(-1)^{n}$ when $t=n\pi$ so the limit does not exist.