• @[email protected]
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    9 months ago

    You’re correct. The square root operator only returns the principal root (the positive one).

    So if x^2 = 9 then x = ±√9 = ±3

    That’s why in something like the quadratic formula we all had to memorize in school its got a “plus or minus” in it: -b ± √…(etc)

    • @[email protected]
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      19 months ago

      So I checked this on my smartphone first, and thought maybe the software is just shit… So then I checked it on a Casio scientific calc, and both agree.

      -3^2 = -9… And 9 != -9

      … Are all the calculators somehow wrong? What’s the math rule I’m forgetting here…

        • @[email protected]
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          39 months ago

          Oh derp. Yep it is.

          Was better when calcs had a +/- button.

          And I remembered the math rule too.

          • @[email protected]
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            19 months ago

            GD I am just realizing how long its been since I did math in my head without a programming language…

            I should take a math class again or something and refresh that knowledge.