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# Complex Number Sum Over the Positive Integers

NUMTH-VBBH@1

What is $\sum_{m = 1}^{n} i^m$? Select ALL that apply.

A

$0$ if $n\equiv 0(\text{mod} 4)$

B

$i$ if $n\equiv 1(\text{mod} 4)$

C

$-1 + i$ if $n \equiv 2(\text{mod} 4)$

D

$-1$ if $n \equiv 3(\text{mod} 4)$