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Submitted ⁨⁨1⁩ ⁨year⁩ ago⁩ by ⁨fossilesque@mander.xyz⁩ to ⁨science_memes@mander.xyz⁩

https://mander.xyz/pictrs/image/7a77a0d9-bf97-4b35-aa7a-8ab42497c005.jpeg

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  • Neato@ttrpg.network ⁨1⁩ ⁨year⁩ ago

    -3 feels like cheating.

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    • ech@lemm.ee ⁨1⁩ ⁨year⁩ ago

      Eh, not really. It’s been a while, but I’m pretty sure the rule in algebra when solving for a squared variable like this is to use ± for exactly that reason.

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    • knorke3@lemm.ee ⁨1⁩ ⁨year⁩ ago

      just wait for roots of imaginary numbers :)

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  • namelivia@lemmy.world ⁨1⁩ ⁨year⁩ ago

    -3 id the hidden character of the solution, like evil ryu or devil jin.

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    • lseif@sopuli.xyz ⁨1⁩ ⁨year⁩ ago

      just a glimpse into my dark and twisted mind

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      • ZILtoid1991@lemmy.world ⁨1⁩ ⁨year⁩ ago

        But for the Joker, that’s the real solution.

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  • Gemini24601@lemmy.world ⁨1⁩ ⁨year⁩ ago

    Doesn’t x also -3?

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    • lugal@lemmy.ml ⁨1⁩ ⁨year⁩ ago

      You found the other

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      • uis@lemm.ee ⁨1⁩ ⁨year⁩ ago

        Now kiss

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    • dankestnug420@lemmy.ml ⁨1⁩ ⁨year⁩ ago

      Sqrt(9)

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      • UnRelatedBurner@sh.itjust.works ⁨1⁩ ⁨year⁩ ago

        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)

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      • Evil_Shrubbery@lemm.ee ⁨1⁩ ⁨year⁩ ago

        Fund the sqrter!

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      • Kusimulkku@lemm.ee ⁨1⁩ ⁨year⁩ ago

        Sqrt

        hehe

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  • Crashumbc@lemmy.world ⁨1⁩ ⁨year⁩ ago

    Also math teacher…

    “Show your work”

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  • merari42@lemmy.world ⁨1⁩ ⁨year⁩ ago

    Middle school math memes

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  • xkforce@lemmy.world ⁨1⁩ ⁨year⁩ ago

    The number of solutions/roots is equal to the highest power x is raised to (there are other forms with different rules and this applies to R and C not higher order systems)

    Some roots can be complex and some can be duplicates but when it comes to the real and complex roots, that rule generally holds.

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    • GnomeKat@lemmy.blahaj.zone ⁨1⁩ ⁨year⁩ ago

      I think you can make arbitrarily complicated roots if you move over to G^n^ which includes the R and C roots…

      For example (3e1e2e3e4)^2 = 9 in G^4^, complex roots are covered because e1e2^2 = -1 making it identical to i so G^n^ (n>=2) includes C.

      G^n^ also includes all the vectors so any vector with length 3 will square to 9 because u^2 = u dot u = |u|^2

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      • ouRKaoS@lemmy.today ⁨1⁩ ⁨year⁩ ago

        You lost me at “arbitrarily complicated,” sorry.

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      • MBM@lemmings.world ⁨1⁩ ⁨year⁩ ago

        I thought this would be related to quaternions, octonions etc. but no, it’s multivectors and wedge products. Very neat, I didn’t know you could use them like that.

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      • someacnt_@lemmy.world ⁨1⁩ ⁨year⁩ ago

        Then you can extend to arbitrary algebra

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    • Beetschnapps@lemmy.world ⁨1⁩ ⁨year⁩ ago

      To translate: As a child learning math this means “ignore math, the explanations don’t explain anything real, they only explain math. So instead focus on language and the arts.”

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      • overcast5348@lemmy.world ⁨1⁩ ⁨year⁩ ago

        I’m guessing that you were one of those “I won’t ever use all this math” kind of students?

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      • Maalus@lemmy.world ⁨1⁩ ⁨year⁩ ago

        Or you were just shit at maths and don’t have any idea how useful it is because you avoid it like the plague.

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  • space@lemmy.dbzer0.com ⁨1⁩ ⁨year⁩ ago

    My teacher explained as sqrt(poop^2) = abs(poop). Yes, he wrote poop on the blackboard.

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    • NeatNit@discuss.tchncs.de ⁨1⁩ ⁨year⁩ ago

      He should have drawn a pile of poop instead 💩 (preferably without a face)

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  • Patrizsche@lemmy.ca ⁨1⁩ ⁨year⁩ ago

    Me, a statistician: “if chi-square equals 9 then chi equals 3… What??”

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  • Sweetpeaches69@lemmy.world ⁨1⁩ ⁨year⁩ ago

    Oh, I know this one! It’s pi!

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    • jol@discuss.tchncs.de ⁨1⁩ ⁨year⁩ ago

      What, no. It’s… Eh close enough.

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    • Reddfugee42@lemmy.world ⁨1⁩ ⁨year⁩ ago

      TAU IS BETTER

      /obligatory

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    • mexicancartel@lemmy.dbzer0.com ⁨1⁩ ⁨year⁩ ago

      Help how do i take factorial of pi

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  • hemko@lemmy.dbzer0.com ⁨1⁩ ⁨year⁩ ago

    -3 = 3

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    • mexicancartel@lemmy.dbzer0.com ⁨1⁩ ⁨year⁩ ago

      Adding 3 on both sides

      3-3=3+3

      0 = 6

      1•0 = 6

      1 = 6/0

      1 = inf

      Multiplying e^(iπ) on both sides,

      e^(iπ) = - inf

      iπ = ln|-inf|

      π = ln|-inf| ÷ i

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      • Maalus@lemmy.world ⁨1⁩ ⁨year⁩ ago

        1/0 isn’t infinity though.

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      • huf@hexbear.net ⁨1⁩ ⁨year⁩ ago

        it starts out okay but 6/0 is not inf.

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      • hemko@lemmy.dbzer0.com ⁨1⁩ ⁨year⁩ ago

        I gotta say half of that goes over my head, but I raise my hat to you

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    • ech@lemm.ee ⁨1⁩ ⁨year⁩ ago

      Absolutely.

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  • bleistift2@feddit.de ⁨1⁩ ⁨year⁩ ago

    This only every got handed down to us as gospel. Is there a compelling reason why we should accept that (-3) × (-3) = 9?

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    • notabot@lemm.ee ⁨1⁩ ⁨year⁩ ago

      You can look at multiplication as a shorthand for repeated addition, so, for example:

      3x3=0 + 3 + 3 + 3 = 9

      In other words we have three lots of three. The zero will be handy later…

      Next consider:

      -3x3 = 0 + -3 + -3 + -3 = -9

      Here we have three lots of minus three. So what happens if we instead have minus three lots of three? Instead of adding the threes, we subtract them:

      3x-3 = 0 - 3 - 3 - 3 = -9

      Finally, what if we want minus three lots of minus three? Subtracting a negative number is the equivalent of adding the positive value:

      -3x-3 = 0 - -3 - -3 - -3 = 0 + 3 + 3 + 3 = 9

      Do let me know if some of that isn’t clear.

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      • bleistift2@feddit.de ⁨1⁩ ⁨year⁩ ago

        This was very clear. Now that I see it, I realize it’s the same reasoning why x^(-3) is 1/(x^3):

        2 × -3 = -6
1 × -3 = -3
0 × -3 = 0
-1 × -3 = +3

        

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      • affiliate@lemmy.world ⁨1⁩ ⁨year⁩ ago
        i think this is a really clean explanation of why (-3) * (-3) should equal 9. i wanted to point out that with a little more work, it’s possible to see why (-3) * (-3) must equal 9. and this is basically a consequence of the distributive law:
        

        0  = 0 * (-3)
   = (3 + -3) * (-3)
   = 3 * (-3) + (-3) * (-3)
   = -9 + (-3) * (-3).

        

        the first equality uses 0 * anything = 0. the second equality uses (3 + -3) = 0. the third equality uses the distribute law, and the fourth equality uses 3 * (-3) = -9, which was shown in the previous comment.
        

        so, by adding 9 to both sides, we get:
        

        9 = 9 - 9 + (-3) * (-3).

        

        in other words, 9 = (-3) * (-3). this basically says that if we want the distribute law to be true, then we need to have (-3) * (-3) = 9.
        

        it’s also worth mentioning that this is a specific instance of a proof that shows (-a) * (-b) = a * b is true for arbitrary rings. (a ring is basically a fancy name for a structure with addition and distribute multiplication.) so,  any time you want to have any kind of multiplication that satisfies the distribute law, you need (-a) * (-b) = a * b.
        

        in particular, (-A) * (-B) = A * B is also true when A and B are matrices. and you can prove this using the same argument that was used above.
        

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    • Davel23@fedia.io ⁨1⁩ ⁨year⁩ ago
      Same reason that a double negative makes a positive.
      

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    • ImplyingImplications@lemmy.ca ⁨1⁩ ⁨year⁩ ago
      Here’s a other example:
      

      A) -3 × (-3 + 3) = ?
      

      You can solve this by figuring out the brackets first.
-3 × 0 = 0
      

      You can also solve this using the distributive property of multiplication, rewriting the equation as
      

      A) -3 × (-3 + 3) = 0
(-3 × -3) + (-3 × 3) = 0
(-3 × -3)  - 9 = 0
(-3 × -3) = 9
      

      If (-3 × -3) didn’t equal 9 then you’d get different answers to equation A depending on what method you used to solve it.
      

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  • Maggoty@lemmy.world ⁨1⁩ ⁨year⁩ ago
    I know the math but I still feel like I’m out of the loop somehow?
    

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    • kszeslaw@szmer.info ⁨1⁩ ⁨year⁩ ago
      (-3)^2 = 9 as well
      

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    • JackbyDev@programming.dev ⁨1⁩ ⁨year⁩ ago
      There’s nothing more to this than linking the star wars quote to the -3. That’s it lol
      

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      • Maggoty@lemmy.world ⁨1⁩ ⁨year⁩ ago
        Oh okay. Don’t mind me trying to over analyze things.
        

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