Wikipedia:Reference desk/Archives/Mathematics/2024 December 4

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December 4

How much is this

$\sum _{k=0}^{n}(-1)^{k}$

37.162.46.235 (talk) 11:00, 4 December 2024 (UTC)

1 for n even, 0 for n odd. For $n\to \infty$ see Grandi's series. --Wrongfilter (talk) 11:18, 4 December 2024 (UTC)

I hope this is not homework. Note that (for finite $n$) this is a finite geometric series.  --Lambiam 21:51, 4 December 2024 (UTC)