• ornery_chemist@mander.xyz
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    2 months ago

    Isn’t the squaring actually multiplication by the complex conjugate when working in the complex plane? i.e., √((1 - 0 i) (1 + 0 i) + (0 - i) (0 + i)) = √(1 + - i2) = √(1 + 1) = √2. I could be totally off base here and could be confusing with something else…

      • candybrie@lemmy.world
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        2 months ago

        Considering we’re trying to find lengths, shouldn’t we be doing absolute value squared?

    • HexesofVexes@lemmy.world
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      2 months ago

      Almost:

      Lengths are usually reals, and in this case the diagram suggests we can assume that A is the origin wlog (and the sides are badly drawn vectors without a direction)

      Next we convert the vectors into lengths using the abs function (root of conjugate multiplication). This gives us lengths of 1 for both.

      Finally, we can just use a Euclidean metric to get our other length √2.

      Squaring isn’t multiplication by complex conjugate, that’s just mapping a vector to a scalar (the complex | x | function).