How is sin(npi/2) = (-1)^((n-1)/2) for odd n?

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The equation sin(nπ/2) = (-1)^((n-1)/2) holds true for odd integers n. This relationship can be derived from the properties of the sine function and its periodicity. Specifically, sin(nπ/2) evaluates to -1 or 1 based on the value of n, confirming the validity of the formula. A proof by induction is a recommended method to establish this relationship rigorously.

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jaejoon89
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I know the MacLaurin series for sin(x) but can't figure out how this reduces to the above (if it does).
 
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sin(npi/2) is going to be equal to -1 or 1, depending on the value of n, right? So the formula seems plausible. You could prove it through induction.
 
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thanks
 

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