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…
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)
Thanks, I haven’t connected the dots to that (±) sign and this problem.
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…
I think your calculator is interpreting that as -(3^2) and not (-3)^2
Oh derp. Yep it is.
Was better when calcs had a +/- button.
And I remembered the math rule too.
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.