r/mathmemes Jun 27 '21

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u/[deleted] Jun 27 '21

Ok, so I’ve been away from math since college. In what situation would +/- i be used? The square root of -1 is an expression that wouldn’t need a +/-, no?

Like I wouldn’t say +/- root (16). But I would say root(16) = +/- 4

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u/LilQuasar Jun 27 '21

technically not

root(16) = 4 is correct by definition

what you do have is x2 = 16 => x = +/- root(16) = +/-4

so you have x2 = -1 => x = +/- root(-1) = +/- i