Afaik sqrt only returns positive numbers, but if you’re searching for X you should do more logic, as both -3 and 3 squared is 9, but sqrt(9) is just 3.
If I’m wrong please correct me, caz I don’t really know how to properly write this down in a proof, so I might be wrong here. :p
(ps: I fact checked with wolfram, but I still donno how to split the equation formally)
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…
Doesn’t x also equal -3?
Sqrt(9)
hehe
Uhm, actually 🤓☝️!
Afaik sqrt only returns positive numbers, but if you’re searching for X you should do more logic, as both -3 and 3 squared is 9, but sqrt(9) is just 3.
If I’m wrong please correct me, caz I don’t really know how to properly write this down in a proof, so I might be wrong here. :p
(ps: I fact checked with wolfram, but I still donno how to split the equation formally)
x^2 = 9
<=>
|x| = sqrt(9)
would be correct.
Cool! Makes sense to me. Honestly, I’ve never done it this way, but it’s so clean. Love it. Thanks.
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.
Fund the sqrter!
You found the other
Now kiss