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whining about math

I have always been annoyed by the statement that sqrt(-1) = i.

Note: I'm perfectly fine with the assertion that i^2 = -1.

in reply to Jonathan Lamothe

whining about math
The reason for this is that by the same logic, I could argue that sqrt(1) = -1. We're either constraining the answer to positive numbers or we're not.
in reply to Jonathan Lamothe

piecewise function definitions are a thing though, like the abs function for instance

abs(x) = x, for all positive x
abs(x) = -x, for all negative x

sqrt(x) = positive y, for all positive x
sqrt(x) = i * sqrt(-x), for all negative x

I also find arctan really weird, because it only works if you fiddle with the domain (yet it clearly does exist, and is useful)

I enjoy the unpleasant feeling I get when I realise that all maths is made up!

in reply to Jonathan Lamothe

whining about math

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