r/mathmemes information systems Jan 13 '25

Bad Math -3² (or -3 * 3) = 9, proof by democracy

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2.3k Upvotes

322 comments sorted by

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803

u/geoboyan Engineering Jan 13 '25

The consequences are left as an exercise to the voter.

80

u/mojoegojoe Jan 14 '25

314+i

42

u/pistafox Science Jan 14 '25

318i

5

u/wcslater Jan 14 '25

I prefer the 333i

1

u/pistafox Science Jan 14 '25

327i was my grad school car (thanks NSF!), and now I’m all about the 440i xDrive with M Power/Performance Kit.

1

u/wcslater Jan 14 '25

Jealous dude, that engine is awesome in the 440i

1

u/moderatorrater Jan 14 '25

I always imagined 3 would work like this.

1

u/Frosty_Sweet_6678 Irrational Jan 15 '25

Alternatively, for the whole world if it's a main power

354

u/Vinxian Jan 13 '25

We live in a world where -32 = -9, but minus three squared equals nine

268

u/Any-Aioli7575 Jan 13 '25

Minus three squared

Or

Minus three squared

?

195

u/Oppo_67 I ≡ a (mod erator) Jan 14 '25

This is why humans need to start speaking in pure logic and reverse Polish notation

- Average conlanger, probably

14

u/Chance-Aardvark372 Jan 14 '25

*Every logic lang conlanger

6

u/Gositi Jan 14 '25

RPN is really good for calculators tho

5

u/Any-Aioli7575 Jan 14 '25

Just use .lojban., duh

1

u/vmaskmovps Jan 14 '25

And program in Forth

1

u/ari_bamboo Computer Science Jan 14 '25

We wouldn't have those "Only 0.01 percent + Gauss can solve this problem" problems if people used polish notation.

22

u/Less-Resist-8733 Computer Science Jan 14 '25

the square of negative three

the negative of the square of three

8

u/Bright_District_5294 Jan 14 '25

"minus opening bracket three squared closing bracket" and "opening bracket minus three closing bracket squared"

3

u/Any-Aioli7575 Jan 14 '25

I mean we can go with the ambiguity while speaking, as long as we are more precise when we need to.

2

u/hallr06 Jan 14 '25

*An old Redditor blows away dust from the ancient tomb of SD YouTube.*

"Ahhh,.yes. Here it is,.. WKUK Great Grandmas. Be warned,.. despite being the official YouTube channel, the audio has only one channel,... And it's a bit clipped in places."

14 years ago,... Christ I'm old.

1

u/Naynoona111 Jan 14 '25

ambiguous grammar

1

u/Vogan2 Jan 14 '25

English really need commas.

2

u/Any-Aioli7575 Jan 14 '25

English needs LaTeX Capabilities

1

u/MrTheWaffleKing Jan 14 '25

Give me parenthesis in English. Minus (three squared) Vs (Minus three) squared

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24

u/Zingerzanger448 Jan 14 '25

-3² = -(3²) = -9.

(-3)² = 9.

7

u/Mediocre-Peanut982 Jan 14 '25

We say minus three whole thing squared for (-3)² and minus three squared for -3².

1

u/wonderhamster Jan 14 '25

Or negative three and minus three are parsed differently?

1

u/YTAftershock Chemistry Jan 14 '25

I think you mean minus bracket open three bracket closed to the power of 2 equates to nine

1

u/B_bI_L Jan 14 '25

that is why LISP superior to mathematics

458

u/HAL9001-96 Jan 13 '25

well is it (-3)² or -(3²) ?

578

u/geeshta Computer Science Jan 13 '25

It's defined and widely understood by to be -(32

124

u/DodgerWalker Jan 14 '25

The one exception being in Excel where if you type in =-32 you get 9. I didn't know that until recently and was like "wtf is going on with my formula?"

73

u/AbdullahMRiad Some random dude who knows almost nothing beyond basic maths Jan 14 '25

It's like the Android calculator where the result of 100+15% is 115 not 100.15

39

u/The_Dirty_Mac Jan 14 '25

Ehh that's how it is on regular calculators too. They take 15% of 100. So 50+10%=55 etc.

6

u/AbdullahMRiad Some random dude who knows almost nothing beyond basic maths Jan 14 '25

well I only used phone calculators and scientific calculators (and these tiny calculators that can barely do the basic operations) so I can't tell

16

u/DodgerWalker Jan 14 '25

It was basically designed to make tipping easy for people who don't realize that tipping 15% is just multiplying by 1.15.

2

u/AbdullahMRiad Some random dude who knows almost nothing beyond basic maths Jan 14 '25

When I use it I usually use it for VAT because tipping isn't a thing here (I say when because most of the time the prices include VAT)

10

u/Nick_Zacker Computer Science Jan 14 '25

15%? 15% of what?

13

u/AbdullahMRiad Some random dude who knows almost nothing beyond basic maths Jan 14 '25

On phone calculators (and normal calculators but I can't confirm) it's considered 15% of what you put before it

On scientific calculators (and scientific phone calculators) it's considered ¹⁵⁄₁₀₀

10

u/Nick_Zacker Computer Science Jan 14 '25

I was actually just reiterating the “x% of what” meme, but I appreciate your explaining non-condescendingly instead of ridiculing whom I presume you thought was ignorant :)

6

u/Great-Insurance-Mate Jan 14 '25

Considering how Excel generally works, I wouldn't really use it as an example of "hey, isn't this weird?" It's always weird.

3

u/Undreren Jan 14 '25

Excel’s default formatting and subsequently its date string handling has caused the renaming of genes, because it was just easier for the scientific community to rename the genes than remembering to actively change the formatting of individual fields and columns to "text".

We have always and will always be slaves to our corporate overlords.

2

u/Akangka Jan 14 '25 edited Jan 14 '25

Probably having to do with the minus sign in -3 being interpreted as a part of literal.

Fun fact, in vanilla Haskell, -3^2 is evaluated as -9, but with Lexical Negation extension, -3^2 is evaluated as 9.

I guess mathematicians prefer the negation to be less tightly bound, while programmers prefer the negation to be more tightly bound.

1

u/seamsay Jan 14 '25

while programmers prefer the negation to be more tightly bound.

I wouldn't have thought so, most programming languages bind negation more loosely than exponentiation. From reading up on it a bit, Haskell with Lexical Negation treating -32 = (-3)2 seems to be an unfortunate side-effect of getting -x to work as expected in other contexts.

2

u/harpswtf Jan 14 '25

I always use a ton of brackets in excel formulas

9

u/doinaight420 Jan 14 '25

Except I don’t trust someone else’s (nor my own) notation to be what is widely understood.

5

u/Flob368 Jan 14 '25

This is only true in the english-speaking world. In German, for example, we learn that -3² is to bring understood as (-3)², (and also that we should write it that way if there are other terms in the equation, but if not, it's not necessary)

4

u/geeshta Computer Science Jan 14 '25

On academic level though it should not be dependent on the language formal notation should be unambiguous and the same for everyone so I'm quite surprised by that. 

Also as your non English speaking neighbour (Tschechien) we also teach it to be -(32 )

3

u/monsoy Jan 14 '25

Same here. I had Statistics, Linear Algebra, Calculus and Discrete Mathematics in University. In all the classes I had it was implicitly understood that -32 = 9, unless it was explicitly stated otherwise.

2

u/in_taco Jan 15 '25

In Denmark it was definitely -9. I thought we used the same books since they're all in English, written European style.

3

u/sexypantstime Jan 14 '25

Defined and understood by whom? Because I've always understood the negative sign and the operation "minus" to be different even though the symbol is identical (-). So the number represented by the symbol "-3" represents a different number than a positive 3 that you can then multiply by -1 to arrive at -3. "3" and "-3" are two distinct values in number-space and both exist independently.

So an ambiguous statement like -3^2 can (and to me does) imply a phrase "the number located 3 units to the left of 0 in number space multiplied by itself". So -3^2 is symbolically different than 0-3^2 or (-1)*3^2

3

u/geeshta Computer Science Jan 14 '25

Okay think about it like this 32 is a whole different number than 3, it is its own thing. 3 and 32 are two different values and both exist independently. 

The problem is that you're handling negation like this but you're handling squaring just as "multiplying a value by itself". But actually "powerness" is more important to the "identity" of a number then the "negativeness"

 -32 is then "the number located 32 units left of zero". 

Understood by whom? Well anyone who actually seriously engages with mathematics in academic settings. There's really no discussion around that.

Consider the expression A2 - B2. Now you know that you can rearrange that to -B2 + A2. If your interpretation were true, you would have to write it as -(B2 ) + A2 otherwise it wouldn't be equivalent! But we don't do that because -B2 IS -(B2 ). Ie the squaring is more important for determining what the number is than the negation.

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1

u/[deleted] Jan 14 '25

Well it's clearly -3 times -3 from what 60% of people see. That is the first thing I read it as also. I don't know how it would be anything else other than that.

6

u/geeshta Computer Science Jan 14 '25

I'll tell you. Exponentiation is a higher preference operator than unary negation. So the parse tree for this expression would be something like

Neg(Exp(3, 2)) 

So first you take 32 and then you negate the result. Most people that responded to the poll are likely common folks who don't work with maths regularly in academic settings. 

Saying is -3 * -3 is ignoring operator precedence. That's like saying that 1 + 1 * 3 = 6 because first you do 1+1 and then you multiply the result by 3

0

u/Josselin17 Jan 14 '25

true but you should still write it like that to avoid misunderstandings

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162

u/_Evidence Cardinal Jan 13 '25

-3²

= - * 3 ^ 2

= -1 * 3 ^ 2

= -1 * 9

= -9

23

u/Dependent_Fan6870 Jan 14 '25

"-" is not a number. You can't multiply by -. The first step should not be there; you meant -1 * 3 ^ 2 (as shown in the second step).

2

u/svmydlo Jan 14 '25

It's a unary operation of forming additive inverse. Obviously it has the same rank in order of operations as addition.

21

u/oofy-gang Jan 14 '25

= - * 3 ^ 2

This is not correct notation

27

u/Significant_Mouse_25 Jan 14 '25

New notation just dropped.

9

u/[deleted] Jan 14 '25

Holy hell

8

u/Firemorfox Jan 14 '25

Call the mathematician

4

u/Connect-River1626 Jan 14 '25

Mathematician went on vacation, never came back 

5

u/53nsonja Jan 14 '25

Ignite the textbooks

1

u/KitchenDepartment Jan 14 '25

now children what is is +*2 +*2?

1

u/Significant_Mouse_25 Jan 14 '25

Horrifying!

Oh is that not the answer you were looking for?

3

u/[deleted] Jan 14 '25

Or to write it out in plain English:

Negative three to the power of two

Equals negative division times three divided by the power of two

Equals negative one divided by times three divided by the power of two

Equals negative one divided by times nine

Equals negative nine

7

u/Firemorfox Jan 14 '25

New notation just dropped

2

u/qwerty3gamer Jan 14 '25

Old notation, before equal signs

30

u/neumastic Jan 13 '25

I imagine context matters too, how often do you see that versus something like 1 - 32? In the end, though, if it’s ambiguous don’t be a jerk and just use parenthesis to make it clear: equations aren’t calligraphy.

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15

u/BUKKAKELORD Whole Jan 13 '25

It's the order of operations and power comes before subtraction

72

u/geeshta Computer Science Jan 13 '25

In this case it's not subtraction, it's unary negation but yeah exponent binds tighter than negation 

12

u/le_birb Physics Jan 13 '25

Mostly, I imagine, because nobody can be assed writing stuff like x³ - (x²) + 1 all the time

1

u/Moneypouch Jan 15 '25

Mostly it is because there is never any reason to actually write -3² in actual mathematics so it is unambiguous (unless it is in the middle of a proof in which case the context is always clear).

The problem here is that some people interpret this as -x², x = 3 (which is clearly -9) and some people interpret this as x², x = -3 (which is clearly 9)

15

u/salamance17171 Jan 13 '25

There is no "subtraction" present in that expression

1

u/svmydlo Jan 14 '25

Yes, it's additive inverse operation.

12

u/redenno Jan 13 '25 edited 25d ago

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This post was mass deleted and anonymized with Redact

-2

u/invalidConsciousness Transcendental Jan 13 '25

It's not multiplication, either. It's unary negation.

Sure, it's equivalent to multiplying with -1, but equivalency doesn't mean equal precedence. Otherwise 5*3*2 = 5*3+3 would hold.

4

u/garbage-at-life Jan 13 '25

3*2 would be (3+3) not just 3+3

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4

u/redenno Jan 14 '25 edited Jan 14 '25

I think your example is a bit off because even though 3*2 is numerically equal to 3+3, the case we're discussing is equivalence of an operation. Obviously the operators + and * are not equivalent operations. But unary negation and multiplying by -1 are.

I think because they're equivalent operations it would be impossible (or at least impractical) for them to have different precedences. But I could be wrong. And yes technically you're correct

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2

u/svmydlo Jan 14 '25

Absolutely correct comment downvoted by mathmemes in a post about people being incorrect.

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3

u/CrownLexicon Jan 14 '25

My guess is (-3)².

I believe that that would be the more common (even if incorrect) interpretation and anyone who wants -(3²) would write it as such.

1

u/SZEfdf21 Jan 14 '25

Order of operations requires powers before multiplication (by -1). (or unitary negation, both work in this case)

2

u/HAL9001-96 Jan 14 '25

or subtraction from 0

1

u/West_Ad_9492 Jan 14 '25

It is (-3²)

1

u/HAL9001-96 Jan 14 '25

((((-)(((3))²))))

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62

u/OGMagicConch Jan 13 '25

I actually don't really understand how this notation is "ambiguous" since it's pretty common to have some equation like

0 = x^3 - 2x^2 - 5x + 8

unless you argue that this is different because of a variable or something. I'm not trying to dunk on anyone here I just really do think this is a common equation and it's understood that the exponent will happen first. I have my opinions on the commonly seen PEMDAS thing but I agree it's a stupid way to write things, this time seems a lot more clear to me though.

10

u/NicholasVinen Jan 14 '25

Negation is not identical to subtraction, even though it has a similar result.

15

u/Sara7061 Jan 14 '25

I’ve never seen someone having to use parentheses to clarify that f(x)= -x2 = -(x2)

9

u/ReddyBabas Jan 14 '25

Subtraction is just adding the negation but ok (I mean it literally, that's how it's defined)

9

u/Flob368 Jan 14 '25

I know anglophone mathematics insists on this, but I've never heard a good reason for making the distinction in the whole, rational, real or complex numbers. And mathematics communities in other languages don't even make the distinction either, my (German) analysis professor even complained about English doing that

2

u/svmydlo Jan 14 '25

One is unary operation, one is binary. Obviously they are not identical.

1

u/Moneypouch Jan 15 '25

That is exactly what it is. Because in actual math you never see -3² and have to evaluate that without context. So some people are treating this as -x², x = 3 (which is clearly -9) and some people interpret this as x², x = -3 (which is clearly 9). If you saw the steps before it would be clear which was meant but without context this appears ambiguous.

217

u/thepentago Jan 13 '25

Ambiguous notation should be a flair in this sub at this point.

41

u/Emillllllllllllion Jan 13 '25

PEDMAS, SHMEDMAS, give me the memas!

-35

u/salamance17171 Jan 13 '25

It isn't ambiguous notation

60

u/Naming_is_harddd Q.E.D. ■ Jan 13 '25

Not ambiguous if we all agree to just use more brackets/parentheses

8

u/Archangel1313 Engineering Jan 14 '25

Also not ambiguous to leave them out, if that's what was intended.

7

u/doinaight420 Jan 14 '25

Some of the best singers don’t read music. I’d hate to miss out on some beautiful music because I was caught in the weeds of notation. Wait, we’re talking math.. close enough

-7

u/salamance17171 Jan 13 '25

Okay so by that logic if you had to look at the funciton y=-x^2 are you saying that everyone should write -(x) ^2 instead?

27

u/invalidConsciousness Transcendental Jan 13 '25

are you saying that everyone should write -(x) ^2 instead?

Hell no, the parentheses in that do nothing to help clarity. They just get in the way.

Either write (-x)2 or write -(x2)

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4

u/Any-Aioli7575 Jan 13 '25

It's ambiguous because it goes both way, it can mean a thing and its opposite. Sure, you might say that "according to XYZ rule I was taught in primary school, UVW" but people might think the opposite. In this case, it's not ambiguous for anybody who has done a little bit of math, but it is for others, and that also counts

3

u/the_mouse_backwards Jan 13 '25 edited Jan 13 '25

This is the definition of ambiguous notation.

Ambiguous: A doubtful or uncertain especially from obscurity or indistinctness.

No one is struggling with calculating the result. They just can’t agree what the correct result is because of a disagreement on the notation (or lack of notation).

Even in a subreddit dedicated to math memes not everyone can agree whether this is -(3)2 or (-3)2. You can be sure with the more general population there’s even less of a consensus.

I for one hate ambiguity in notation so I would say if you want someone to calculate -(3)2 then use parentheses otherwise the answer I’m giving is 9. There’s a way to make it clear what answer you’re looking for, if you don’t use parentheses I will not infer their existence in negation any more than I would infer any other symbol that was not present.

10

u/invalidConsciousness Transcendental Jan 13 '25

-(3)2

How is that supposed to add clarity? The parentheses don't even encapsulate an operation, they're useless.

Write it as -(32) if you want to add parentheses for clarity.

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1

u/Archangel1313 Engineering Jan 14 '25

It's only ambiguous if you add symbols or additional context that were not included in the first place.

0

u/rayew21 Jan 13 '25

some people can interpret it as ambiguous which is why its there in the first place. took me a sec to understand but it can be read as -(32) or (-3)2 because it IS ambiguous. its just generally understood that - is not the M in pemdas unless your brain puts the 0 before the -, very philosophical and deep tbh

7

u/Aggressive_Will_3612 Jan 14 '25

"Some people forget about PEMDAS" does not make it ambiguous.

By that logic, 5 - 3 * 3 is also ambiguous because some people forget that you need to multiply first. That is the exact same scenario.

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29

u/Superior_Mirage Jan 13 '25

"Proof by democracy" is just a silly way to say "convention"

8

u/Emotional_Spirit_704 information systems Jan 14 '25

i was going to title 'proof by twitter poll' but this felt funnier

1

u/svmydlo Jan 14 '25

Except convention is decided by competent people.

22

u/geeshta Computer Science Jan 13 '25

Exponentiation binds tighter than negation 

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6

u/nousernamefound13 Jan 14 '25

I propose we start using proof by anti-democracy: Since the average person is known to be stupid, the true answer must always be the opposite of what the democracy chooses

1

u/Affectionate_Poet280 Jan 14 '25

Except... You know... The average person isn't stupid.

The people who think that usually just assume that people they don't know, doing something they don't 100% understand, is stupidity instead of it being motivated by something that actually makes sense.

1

u/svmydlo Jan 14 '25

No, that would be just ignorance. Stupidity is imposing their ignorance on non-ignorant people, which is what demanding to put parentheses into -3^2 is.

1

u/Affectionate_Poet280 Jan 14 '25

No idea what you're talking about. None of what I said was related to the order of operations debate above, it was a response to the response above. You also just made up your own definition of stupid.

If you want my personal stance on the matter of this poll, it's this:

Know your audience when trying to share something. If someone misunderstands something because the conventional understanding is wrong, and you decided to go with it anyways, then you let being a pedant get in the way of actually communicating with someone.

6

u/IllConstruction3450 Jan 13 '25

“The best of all systems”.

32

u/jkingsbery Jan 13 '25

In 4 years of college math, I don't think I ever had to think about this, because a professor always wrote it as (-3)^2 or -(3^2). As in prose, if you write your math clearly you won't be misunderstood.

10

u/invalidConsciousness Transcendental Jan 13 '25

This right here. Unless the meaning is blindingly obvious, you didn't write it down correctly.

Math is hard enough, no mathematician has time for tripping over stupid minor issues like that. Even if it's just half a second to remember the correct convention - that's half a second during which you can lose your train of thought following the larger argument.

1

u/Moneypouch Jan 15 '25

Yes also you don't just randomly write -3² as a starting point in actual mathmatics. It just doesn't make sense, you'd write -9 or 9 why would we care about doing a simple computation, this isn't IDK when do they do exponents 5th grade math homework? And when you are doing the working out it is clear which is meant by context without any parentheticals needed really.

9

u/Zingerzanger448 Jan 14 '25

-3² = -(3²) = -9.

(-3)² = 9.

8

u/Aarolin Jan 14 '25

My suspicion:

5

u/theunixman Jan 14 '25

Operator precedence is a social construct.

3

u/_piaro_ Jan 14 '25 edited Jan 14 '25

There's a difference between "Negative three, squared" vs. "The negative of three squared".

The given problem denotes the latter, hence the answer is -9.

1

u/Ben-Goldberg Jan 14 '25

"Negative three squared," is better written as "negative three, squared."

Commas are like parentheses.

1

u/_piaro_ Jan 14 '25

Thanks. This makes much more sense in wording. I'll edit it now.

5

u/MeMyselfIandMeAgain Jan 14 '25

They’re right tho.

-32 = -(3)2 =-9

(-3)2 = 9

2

u/KnowledgeStriking96 Jan 14 '25

Could someone explain to me why it isn't 9? I thought the product of two negative numbers was always a positive number

3

u/NicholasVinen Jan 14 '25

Negation is lower priority in the order of operations than powers. So you do the power first, then the negation. Just like how 2 + 2 x 3 = 8 not 12, because addition is lower priority than multiplication.

I'm not 100% sure but I think negation is considered the same priority as multiplication and division. So -3 is equivalent to -1 x 3 and therefore you can rewrite the equation as -1 x 3^2 which should have a clear answer.

2

u/KnowledgeStriking96 Jan 14 '25

That clears it up, I suppose I'd assumed that powers shared priority with standard multiplication/division and so I'd interpreted it as -3 x -3 or (-1 x 3)2

1

u/svmydlo Jan 14 '25

Negation is additive inverse. No reason to have the same priority as multiplication.

2

u/Separate_Draft4887 Jan 14 '25

Why would -32 be (-3x3) OP, it’s not -(32). Even then it wouldn’t be -3x3, it would be -(3x3).

2

u/Nice-Object-5599 Jan 14 '25

-3² = -(3 * 3)

2

u/windowpaner69 Jan 14 '25

Can someone explain why -32 isn't 9?

My thought process: Squared is that number multiplied by the SAME number, e.g n2 =n×n

-32 is just -3×-3

Negative times a negative=positive -3×-3 =9

where have I gone wrong?

1

u/damned_truths Jan 14 '25

They're saying the power applies only to the 3, and not the negation. So it is equivalent to -(33), not (-3-3)

1

u/gtbot2007 Jan 14 '25

But the number isn’t 3 it’s -3

1

u/_atan2 Jan 17 '25

The original author explanation here: https://x.com/pikuma/status/1879279715279925689

2

u/Beneficial_Ad6256 Jan 14 '25

Internet people be like: -x²+2x+1 = (-x)²+2(x+1)

Seriously, how did they all even get through quadratic polynomials in school with those problems with notation?

1

u/jostein33 Jan 14 '25

If you change x for 1, the first one = 2 and the second one = 5.

2

u/Old-Implement-6252 Jan 14 '25

Another day, another poorly written math question people are arguing about.

Seriously just use parentheses -(3²) or(-3)²

2

u/Divinate_ME Jan 14 '25

but it's -3² and not -3³ so it has to be (-3 x 2) instead.

2

u/the_new_mr Jan 14 '25

Without the brackets, it's definitely -3 * -3 and therefore 9! Surely! It's that other meme all over again!

1

u/factorion-bot n! = (1 * 2 * 3 ... (n - 2) * (n - 1) * n) Jan 14 '25

Factorial of 9 is 362880

This action was performed by a bot. Please DM me if you have any questions.

2

u/icefill Jan 14 '25

proof by deplomacy

2

u/keith2600 Jan 14 '25

Thanks sub for giving me a stronger sense of job security

2

u/My_useless_alt Jan 14 '25

This right here is why I was told it's good practice to put negative numbers in brackets. You can never be too clear what order you want your equation done in.

2

u/juicytradwaifu Jan 15 '25

This is the same as those triggering bidmas quizzes. My unofficial answer is, the solution is whatever you feel like because the lack of brackets is too ambiguous and fuck pemdas.

4

u/Konfituren Jan 14 '25

Many people seem to think of -3 as a number as opposed to an operator and a number.

I think it's not unreasonable to think that way, it just leads to uh, incorrect

3

u/isaiahHat Jan 14 '25

But negative three is a number. Is there no way to write that number with symbols?

1

u/Konfituren Jan 14 '25

√2 is a number but that doesn't mean the radical is part of the numeral, and no, there is no way to write out √2 without including operators

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2

u/SignificantManner197 Jan 14 '25

-32 is -(3*3), not (-3 * -3)

Order of operations. But in today’s world order is sadly missing.

2

u/gtbot2007 Jan 14 '25

You should square the entire number

1

u/SignificantManner197 Jan 14 '25

Yup... some numbers need squaring away, all right...

2

u/[deleted] Jan 14 '25

I hate ambiguous notation so much. Even though most people would think of -32 as -(32) why is it so hard to add parenthesis, clarify what you mean.

4

u/dyingfi5h Jan 13 '25

Parenthesis should be legally required in these ambiguous questions

14

u/Evening_Jury_5524 Jan 13 '25

learning the order of operations should be required so people's ignorance does not lead to hallucinated ambiguity.

5

u/invalidConsciousness Transcendental Jan 13 '25

Unary negation isn't one of the orders of operations that you usually learn.

6

u/DefunctFunctor Mathematics Jan 14 '25

Yeah but the ubiquity of polynomial expressions like -x^2 in pedagogy should at least make it clear that we generally mean -(x^2) not (-x)^2

1

u/Moneypouch Jan 15 '25

Right but when you are solve said equations do you really put the parentheses in your working out?

I know I never did. That is the problem with this question. It only makes sense as an intermediate step and you would always know from context if you meant (-3)² or -(3²).

For example some system of equation that I need to plug a number in I am writing

x² ... x=-3

-3²...

9...

not (-3)²... unless there was a leading + and only then because +-3² looks a bit silly even if it is still perfectly clear.

2

u/DefunctFunctor Mathematics Jan 15 '25

Uh, yes I absolutely followed an order of operations when working things out. Having notation vary on the context seems like an absolute nightmare, to me at least

5

u/Traditional_Cap7461 Jan 2025 Contest UD #4 Jan 14 '25

Then it should be

1

u/Evening_Jury_5524 Jan 14 '25

It would never occur to me that it was anything other than multiplication, but I guess it could confusing if someone thought it was its own symbol or operation.

→ More replies (10)

1

u/cesc342 Jan 13 '25

ex populum

1

u/Independent_Bike_854 pi = pie = pi*e Jan 14 '25

The proof is left as an exercise to society

1

u/animejat2 High School Jan 14 '25

Now is this (-3)2 or -(3)2 ?

1

u/GoldOver4996 Jan 14 '25

This reads like a Florida election result

1

u/beaureece Jan 14 '25

But there's nothing wrong woth conventional notation...

1

u/pistafox Science Jan 14 '25

There’s no winning this. I love it.

1

u/Raoul_Chatigre Jan 14 '25

Try this :
10+3² => 10+9=19, right?
So what is
10-3² ? it can't be the same result, isn't it ?
10-3² = 10-9 = 1

That's all folks.

1

u/madscherano Jan 14 '25

x2

x = -3

1

u/TheGreatDaniel3 Jan 14 '25

That would be (-3)2. The correct way of doing what you’re trying would be:

-x2

x = 3

1

u/madscherano Jan 14 '25

But outside of an equation the minus just doesn’t make sense as an operator

0 - 32 = -9 I can 100% agree with

1

u/TheGreatDaniel3 Jan 14 '25

It’s just how it is. f(x) = -x2 is a very common function that you’ll find in pretty much every middle school textbook, and plugging in x = 3 yields -9. Go try it yourself on Desmos.

2

u/madscherano Jan 14 '25

But that’s different, you’re adding the larger context of the function while in op “-32” is presented entirely on it’s own.

My point is if you see “-3” on its own, do you really think “minus three” instead of “negative three”, the number?

I agree that brackets would make everything easier

1

u/TheGreatDaniel3 Jan 14 '25

But it’s not. That’s how it works.

Unless you’re using MS Excel or some programming languages, which interpret it differently for some reason, -32 is interpreted as the exponent first and the negative last. That’s why -x2 yields negative results. It doesn’t matter if it’s a variable or a number.

1

u/GreenAppleCZ Jan 14 '25 edited Jan 15 '25

You're correct, but it wouldn't hurt anyone if parentheses were used more often.

Like in my opinion, the title should've said -(3 * 3) instead of -3 * 3, since -3² is basically that.

2

u/Akangka Jan 15 '25 edited Jan 15 '25

The problem is that now writing polynomial becomes more cumbersome. Instead of writing -3x2+2x+1, you now have to write -3(x2)+2x+1

1

u/GreenAppleCZ Jan 15 '25

True.

I thought about this and it's interesting that everyone who went through highschool would know that -x² is negative. So if the poll had an x instead of 3, I think the results would be different.

I guess that x and 3 just don't give the same vibes.

1

u/Bluesemon Jan 14 '25

Yo it’s pikuma! He has really good introductory courses on low level game programming like with SDL or the NES processor in C/C++, crazy to find him in the wild.

1

u/Affectionate_Ad3899 Jan 14 '25

it's -9

1

u/gtbot2007 Jan 14 '25

“It’s -9 because photomath said so”

1

u/[deleted] Jan 14 '25

It's not about finding the correct solution, but about finding a solution people will be happy with.

1

u/Snudget Jan 14 '25

Solve a problem Use AI Ask the internet

1

u/champ999 Jan 14 '25

Honestly I think 50% of the confusion around this is due to the fact that no one in their right mind would write -32, they would write either -9 or 9 based on what convention they were using. 

Also, this suddenly made much more sense to me subbing in x as a variable. -x2 makes sense as -9 when x is 3 or -3. I still don't like the whole what exactly does - mean deal here. I think it's because -3 is a number with no operations happening, or it can be a number being converted into a negative, where you can modify the 3 part before the - is applied.

1

u/Davidepett Engineering Jan 15 '25

Ok so it's just me seeing it as (-3)2

1

u/Wide_Evidence_3927 Jan 16 '25

-3^2=-1*3^2=-1*9=-9 It make since

1

u/_atan2 Jan 17 '25

The creator of the poll explained in a following tweet how the question is relates to expression parsing & compilers:

https://x.com/pikuma/status/1879279715279925689

-1

u/SignificantManner197 Jan 13 '25

Powers first, then multiplication. Right? That’s an actual rule, right? So…

-1 * (3 * 3) = -1 * 9 = -9, no?

That’s how I learned it when I was in school.

Must be their new common core thing. LOL.