SmartmanApps comments on I dunno

You seem to be getting confused because none of the examples on this particular page feature the multiplication symbol ×. But that is because on the previous page, the author writes:

When a product involves a variable it is customary to omit the symbol × of multiplication.

That means that the expression bc is just another way of writing b×c; it is treated the same other than requiring fewer strokes of the pen or presses on a keyboard, because this is just a custom. That should clear up your confusion in interpreting this textbook (though really, the language is clear: you don't dispute that b×c - or b * c - are products, do you.)

Elsewhere in this thread you are clearly confused about what brackets mean. They are explained on page 20 of your textbook, where it says that you evaluate the expression inside the (innermost) brackets before doing anything else. Notice that, in its elucidation of several examples, involving addition and multiplication, the "distributive law" is not mentioned, because the distributive law has nothing to do with brackets and is not an operation.

Thus the expression 3 × (2 + 4) can be evaluated by first performing the summation inside the brackets to get 3 × 6 and then the product to get 18. The textbook then says that it is customary to omit the multiplication symbol and instead write 3(2+4), again indicating that these expressions are merely different ways of writing the same thing.

The exact same process of course must be followed whether numbers are represented by numerals or by letters designating a variable. You cannot do algebra if you don't follow the same procedure in both cases. So consider the expression 2(a+b)². You have suggested that you must evaluate this as (2a+2b)² because you must "do brackets first", but this is not what "doing brackets" means. You haven't produced any authority to suggest that it is, and your own textbook makes it clear that "doing brackets" means do what is inside the brackets first. Not what is outside the brackets. Distributing 2 over a+b is not "doing brackets"; it is multiplication and comes afterwards.

If 2(a+b)² were equal to (2a+2b)² let us try with a=b=2. Let us first evaluate (2a+2b)²: it is equal to (2×2+2×2)² = (4+4)² = 8² = 64. Now let us evaluate 2(a+b)²: it is 2(2+2)² and now, following your textbook's instruction to do what is inside the brackets first, this is equal to 2(4)². The next highest-priority operation is the exponent, giving us 2×16 (we now must write the × because it is an expression purely in numerals, with no brackets or variables) which is 32.

The fact that these two answers are different is because your understandings of what it means to "do brackets" and the distributive law are wrong.

Since I'm working off the textbook you gave, and I referred liberally to things in that textbook, I'm sure if you still disagree you will be able to back up your interpretations with reference to it.

By the way, I noticed this statement on page 23, regarding the order of operations:

However, mathematicians have agreed on a rule to fall back on if someone omits punctuation marks.

it does rather seem like this rule is one established not by the fundamental laws of mathematics but by agreement as they say, does it not? Care to comment?

permalink

fedilink

source

parent

hideshow 32 child comments

[–] SmartmanApps@programming.dev 0 points 10 months ago (25 children)

So b * c, which is a product of the variables b and c

Nope. bc is the product of b and c. bxc is Multiplication of the 2 Terms b and c.

according to this textbook

Says person who clearly didn't read more than 2 sentences out of it 🙄

none of the examples on this particular page feature the multiplication symbol ×

and why do you think that is? Do explain. We're all waiting 😂 Spoiler alert: if you had read more than 2 sentences you would know why

That means that the expression bc is just another way of writing b×c;

No it doesn't. it means bxc is Multiplication, and bc is the product 🙄 Again you would've already known this is you had read more than 2 sentences of the book.

it is treated the same other than requiring fewer strokes of the pen

No it isn't, and again you would already know this if you had read more than 2 sentences. If a=2 and b=3, then...

1/ab=1/(2x3)=1/6

1/axb=1/2x3=3/2

this is just a custom

Nope, an actual rule of Maths. If you meant 1/axb, but wrote 1/ab, you've gonna get a different answer 🙄

That should clear up your confusion in interpreting this textbook

says person who only read 2 sentences out of it 🙄

though really, the language is clear:

It sure is when the read the rest of the page 🙄

you don’t dispute that b×c - or b * c - are products, do you

What don't you understand about only ab is the product of a and b?

Elsewhere in this thread you are clearly confused about what brackets mean

Not me, must be you! 😂

They are explained on page 20 of your textbook, where it says that you evaluate the expression inside the (innermost) brackets before doing anything else.

Until all brackets have been removed. on the very next page. 🙄 See what happens when you read more than 2 sentences out of a textbook? Who would've thought you need to read more than 2 sentences! 😂

the “distributive law” is not mentioned, because the distributive law has nothing to do with brackets

And yet, right there on Page 21, they Distribute in the last step of removing Brackets, 🙄 5(17)=85, and throughout the whole rest of the book they write Products in that form, a(b) (or just ab as the case may be).

is not an operation

Brackets aren't an operator, they are grouping symbols, and solving grouping symbols is done in the first 2 steps of order of operations, then we solve the operators.

Thus the expression 3 × (2 + 4) can be evaluated by first performing the summation inside the brackets to get 3 × 6 and then the product to get 1

3x6 isn't a Product, it's a Multiplication, done in the Multiplication step of order of operations.

The textbook then says that it is customary to omit the multiplication symbol and instead write 3(2+4)

It says you omit the multiplication sign if it's a Product, and 3x6 is not a Product. I'm not sure how many times you need to be told that 🙄

again indicating that these expressions are merely different ways of writing the same thing

Nope, completely different giving different answers

1/3x(2+4)=1/3x6=6/3=2

1/3(2+4)=1/3(6)=1/18

You have suggested that you must evaluate this as (2a+2b)² because you must “do brackets first”

Yep

this is not what “doing brackets” means.

Yes it is! 😂

Not what is outside the brackets.

Yes it is! 😂 Until all Brackets have been removed, which they can't be if you haven't Distributed yet. Again, last step of the working out...

Distributing 2 over a+b is not “doing brackets”;

Yes it is! 😂 Until all Brackets have been removed

it is multiplication and comes afterwards

Nope, it's Distribution, done in the Brackets step, before doing anything else, as per Page 21

following your textbook’s instruction to do what is inside the brackets first, this is equal to 2(4)²

Which, when you finish doing the brackets, is 8²

The next highest-priority operation is the exponent

After you have finished the Brackets 🙄

giving us 2×16

Nope. Giving us 8²=64

we now must write the × because it is an expression purely in numerals

Nope! If you write it at all, which you don't actually need to (the textbook never does), then you write (2x4)², per The Distributive Law, where you cannot remove the brackets if you haven't Distributed yet. There's no such rule as the one you just made up

The fact that these two answers are different is because

You disobeyed The Distributive Law in the second case, and the fact that you got a different answer should've been a clue to you that you did it wrong 🙄

what it means to “do brackets” and the distributive law are wrong

No, that would be your understanding is wrong, the person who only read 2 sentences 🙄 I'm not sure what you think the rest of the chapter is about.

Since I’m working off the textbook you gave

Says person who only read 2 sentences out of it 🙄

I referred liberally to things in that textbook

Yep, ignoring all the parts that prove you are wrong 🙄

I’m sure if you still disagree you will be able to back up your interpretations with reference to it

Exact same reference! 😂

it does rather seem like this rule is one established not by the fundamental laws of mathematics but by agreement as they say

You know Mathematicians tend to agree when something has been proven, right? 😂

Care to comment?

Yep, read the whole chapter 🙄

permalink

fedilink

source

parent

hideshow 25 child comments

[–] FishFace@piefed.social 1 point 10 months ago* (last edited 10 months ago) (3 children)

Do you teach classes like this? "That's not a product, it's a multiplication" -- those are the same thing. Shouldn't you, as a teacher, be explaining the difference, if you say there is one? I'm starting to believe you don't think they're is one, but are just using words to be annoying. Or maybe you don't explain because you don't know.

You could argue that "product" refers to the result of the multiplication rather than the operation, but there's no sense in which the formula "a × b" does not refer to the result of multiplying a and b.

Of course, you don't bother to even make such an argument because either that would make it easier to see your trolling for what it is, or you're not actuality smart enough to understand the words you're using.

It's interesting, isn't it, that you never provide any reference to your textbooks to back up these strange interpretations. Where in your textbook does it say explicitly that ab is not a multiplication, or that a multiplication is different from a product in any substantive sense, eh? It doesn't, does it? You're keen to cite textbooks any time you can, but here you can't. You complain that people don't read enough of the textbook, yet they read more than you ever refer to.

In the other thread I said I wouldn't continue unless you demonstrated your good faith by admitting to a simple verifiable fact that you got wrong. Here's another option: provide an actual textbook example where any of the disputed claims you make are explicitly made. For example, there should be some textbook somewhere which says that mathematics would not work with different orders of operations - you've never found a textbook which says anything like this, only things like "mathematicians have agreed" (and by the way, hilarious that you commit the logical fallacy of affirming the consequent on that one).

Likewise with your idea of what constitutes a term, where's your textbook which says that "a × b is not a term"? Where is the textbook that says 5(17) requires distribution? (All references you have given are that distribution relates multiplication and addition, but there's no addition) Where's your textbook which says "ab is a product, not multiplication"? Where's a citation saying "product is not the same as multiplication and here's how"? Because there is a textbook reference saying "ab means the same as a × b", so your mental contortions are not more authoritative.

Find any one of these - explicitly, not implicitly, (because your ability to interpret maths textbooks is poor) and we can have a productive discussion, otherwise we cannot.

My prediction: you'll present some implicit references and try to argue they mean what you want. In that case, my reply is already prepared 😁

permalink

fedilink

source

parent

hideshow 3 child comments

[–] SmartmanApps@programming.dev -1 points 10 months ago (2 children)

Do you teach classes like this? “That’s not a product, it’s a multiplication”

Yep! And if you read more than 2 sentences out of the textbook you would know why 🙄

those are the same thing.

Says person who only read 2 sentences out of a whole chapter 🙄

Shouldn’t you, as a teacher, be explaining the difference, if you say there is one?

Yep, and it's right there in the textbook! 🙄

I’m starting to believe you don’t think they’re is one

So you think if a=2 and b=3, then...

1/ab=1/(2x3)=1/6

1/axb=1/2x3=3/2

Are somehow the same answer?? 😂 Which one is it then? 1/6 or 3/2?? 😂

You could argue that “product” refers to the result of the multiplication rather than the operation

Yep by definition!

there’s no sense in which the formula “a × b” does not refer to the result of multiplying a and b

There's no sense in which it does refer to the result you mean. The result of axb is ab. If a=2, b=3, axb=ab. 2x3=6, axb=2x3, ab=6

you don’t bother to even make such an argument

Says someone revealing that they haven't read a word I've said 🙄

you’re not actuality smart enough to understand the words you’re using

says someone who has just proven they haven't been reading them 🙄

It’s interesting, isn’t it, that you never provide any reference to your textbooks to back up these strange interpretations

Yes I did, and you only read 2 sentences out of it 😂

Where in your textbook does it say explicitly that ab is not a multiplication

Read on dude, read on, like I have been telling you the whole time. Oh wait, that would prove you were wrong. Oh, I wonder why you haven't read it... 🙄

It doesn’t, does it?

The page that you only read one sentence from 🙄

You’re keen to cite textbooks any time you can, but here you can’t

I already did and you only read 2 sentences out of it 🙄

You complain that people don’t read enough of the textbook, yet they read more than you ever refer to

says person who has repeatedly proven they've only read 2 sentences 🙄

In the other thread I said I wouldn’t continue unless you demonstrated your good faith by admitting to a simple verifiable fact that you got wrong

And I pointed out that in fact you got it wrong, and Mr. Hypocrite has failed to admit it 🙄

provide an actual textbook example where any of the disputed claims you make are explicitly made

Same one I already told you and you only read 2 sentences out of a whole chapter

there should be some textbook somewhere which says that mathematics would not work with different orders of operations

It's easy enough to prove yourself, like I did. Go ahead and try it out and let me know how you go.

you’ve never found a textbook which says anything like this

No, I was able to prove it myself 🙄

only things like “mathematicians have agreed”

Because it was proven 🙄

where’s your textbook which says that “a × b is not a term”?

Same textbook that you only read 2 sentences from

Where is the textbook that says 5(17) requires distribution?

It tells you tight there on the same page that you must remove all brackets, 🙄 which you also haven't admitted to being wrong about yet, surprise, surprise, surprise

Where’s your textbook which says “ab is a product, not multiplication”?

Same one you only read 2 sentences from

there is a textbook reference saying “ab means the same as a × b”,

And you stopped reading at that point didn't even finish the page, never mind the chapter 🙄 Just started making false claims (contradicted by same textbook) that "means" means "equals", instead of realising they have explicitly not said equals 🙄

so your mental contortions are not more authoritative

Says person who made the mental contortion that "means" means "equals" instead of reading the rest of the page

your ability to interpret maths textbooks is poor

says person who only read 2 sentences out of a whole chapter 🙄

we can have a productive discussion

when you decide to read more than 2 sentences 🙄

My prediction: you’ll present some implicit references

Wrong, as usual

try to argue they mean what you want

says person trying to argue that "means" means "equals" 🙄

permalink

fedilink

source

parent

hideshow 2 child comments

[–] FishFace@piefed.social 1 point 10 months ago

It's amazing that you think these are explicit references. Notice how the text never says "you MUST use the distributive law"? It always says some variation of "in order to simplify, you must..."?

No, you don't notice, because you're blind, and don't understand what distributivity actually is.

You also got me confused with someone else trying to explain in short words how you're wrong, but that won't be a problem now you demonstrated such abject failure to hold a productive discussion - bye.

permalink

fedilink

source

parent

[–] mindbleach@sh.itjust.works 1 point 10 months ago*

There’s no sense in which it does refer to the result you mean.

"a X b is written ab." Modern Algebra: Structure And Method, page 36. It's only a different way of writing the exact same thing.

Go ahead and try it out and let me know how you go.

Every textbook ever written disagrees with how you think brackets work, and mathematics has not collapsed in on itself. We've seen your Mastodon posts lamenting how 'university people' all disagree with what you lie to teenagers about. All of them! Weird, right? What a bizarre coincidence. I'm not sure what would look different if you were just plain full of shit.

permalink

fedilink

source

parent

[–] mindbleach@sh.itjust.works 0 points 10 months ago (20 children)

none of the examples on this particular page feature the multiplication symbol ×

and why do you think that is?

"When a product involves a variable, it is customary to omit the symbol X of multiplication. Thus, 3 X n is written 3n and means three times n, and a X b is written ab and means a times b."

Illiterate fraud.

permalink

fedilink

source

parent

hideshow 20 child comments

[–] SmartmanApps@programming.dev 0 points 10 months ago (19 children)

Illiterate fraud

says person who thinks "means" and "equals" mean the same thing 😂

permalink

fedilink

source

parent

hideshow 19 child comments

[–] mindbleach@sh.itjust.works 0 points 10 months ago (18 children)

By all means, humiliate yourself by splitting that hair.

permalink

fedilink

source

parent

hideshow 18 child comments

[–] SmartmanApps@programming.dev 0 points 10 months ago (17 children)

By all means, humiliate yourself by splitting that hair

I'll take that as an admission that you're wrong then, given you can't defend your wrong interpretation of it (which you would know is wrong if you had read more than 1 paragraph of the book!) 😂

permalink

fedilink

source

parent

hideshow 17 child comments

[–] mindbleach@sh.itjust.works 1 point 10 months ago (16 children)

This is you admitting there's no difference. You insist they're not the same. How?

permalink

fedilink

source

parent

hideshow 16 child comments

[–] a comment that isn't shown here: deleted, from someone you've blocked, or on another page. view the thread from it

[–] mindbleach@sh.itjust.works 1 point 10 months ago* (14 children)

That's convention for notation, not a distinction between a*b and ab both being the product of a and b.

You have to slap 1/ in front of things and pretend that's the subject, to avoid these textbooks telling you, ab means a*b. They are the same thing. They are one term.

permalink

fedilink

source

parent

hideshow 14 child comments

[–] SmartmanApps@programming.dev 0 points 10 months ago (13 children)

That’s convention for notation

Nope, still rules

not a distinction between a*b and ab

says person who only read 2 sentences out of the book, the book which proves the statement wrong 😂

a*b and ab both being the product of a and b

Nope, only ab is the product, and you would already know that if you had read more than 2 sentences 😂

You have to slap 1/ in front of things and pretend that’s the subject

"identically equal", which you claimed it means, means it will give the same answer regardless of what's put in front of it. You claimed it was identical, I proved it wasn't.

avoid these textbooks telling you

It kills you actually, but you didn't read any of the parts which prove you are wrong 🙄just cherry pick a couple of sentences out of a whole chapter about order of operations 🙄

They are the same thing. They are one term

Nope! If they were both 1 term then they would give the same answer 🙄

1/ab=1/(axb)=1/(2x3)=1/6

1/axb=1/2x3=3/2=1.5

Welcome to why axb is not listed as a Term on Page 37, which if you had read all the pages up until that point, you would understand why it's not 1 Term 🙄

permalink

fedilink

source

parent

hideshow 13 child comments

[–] mindbleach@sh.itjust.works 0 points 10 months ago* (12 children)

'If a+b equals b+a, why is 1/a+b different from 1/b+a?'

ab means a*b.

That's why 1/ab=1/(a*b).

But we could just as easily say 1/ab = (1/a)*b, because that distinction is only convention.

None of which excuses your horseshit belief that a(b)^2^ occasionally means (ab)^2^.

permalink

fedilink

source

parent

hideshow 12 child comments

[–] SmartmanApps@programming.dev 0 points 10 months ago (11 children)

‘If a+b equals b+a, why is 1/a+b different from 1/b+a?’

Because they're not identically equal 🙄 Welcome to you almost getting the point

ab means a*b

means, isn't equal

That’s why 1/ab=1/(a*b)

Nope, it's because ab==(axb) <== note the brackets duuuhhh!!! 😂

But we could just as easily say 1/ab = (1/a)*b

No you can't! 😂

because that distinction is only convention

Nope! An actual rule, as found not only in Maths textbooks (see above), but in all textbooks - Physics, Engineering, Chemistry, etc. - they all obey ab==(axb)

None of which excuses your horseshit belief that a(b)2

says person still ignoring all these textbooks

permalink

fedilink

source

parent

hideshow 11 child comments

[–] mindbleach@sh.itjust.works 0 points 10 months ago* (10 children)

No you can’t!

Yes we could, because it's a theoretical different notation. Mathematics itself does not break down, if you have to put add explicit brackets to 1/(ab).

Mathematics does break down when you insist a(b)^2^ gets an a^2^ term, for certain values of b. It's why you've had to invent exceptions to your made-up bullshit, and pretend 2(8)^2^ gets different answers when simplified from 2(5+3)^2^ versus 2(8*1)^2^.

permalink

fedilink

source

parent

hideshow 10 child comments

[–] SmartmanApps@programming.dev 0 points 10 months ago (9 children)

Yes we could

No you can't! 😂

it’s a theoretical different notation

In other words against the rules of Maths that we have, got it

does not break down, if you have to put add explicit brackets to 1/(ab)

But it does breakdown if you treat ab as axb 🙄

if you have to put add explicit brackets to 1/(ab)

We explicitly don't have to, because brackets not being needed around a single Term is another explicit rule of Maths, 🙄 being the way everything was written before we started using Brackets in Maths. We wrote things like aa/bb without brackets for many centuries. i.e. they were added on after we had already defined all these other rules centuries before

Mathematics does break down when you insist a(b)2 gets an a2 term

No it doesn't. If you meant ab², then you would just write ab². If you've written a(b)², then you mean (axb)²

for certain values of b

Got nothing to do with the values of b

It’s why you’ve had to invent exceptions to your made-up bullshit

says person still ignoring all these textbooks

pretend 2(8)2

There's no pretending, It's there in the textbooks

when simplified from 2(5+3)2 versus 2(8*1)2

You know it's called The Distributive Property of Multiplication over additon, right? And that there's no such thing as The Distributive Property of Multiplication over Multiplication, right? You're just rehashing your old rubbish now

permalink

fedilink

source

parent

hideshow 9 child comments

[–] FishFace@piefed.social 1 point 10 months ago (3 children)

Couldn't resist:

but when multiplications are denoted by juxtaposition, as in 4c ÷ 3ab

Damn, and I thought they were called "products" not "multiplications" 🤔🤔🤔

No it doesn’t. If you meant ab², then you would just write ab². If you’ve written a(b)², then you mean (a×b)²

If you can find an explicit textbook example where writing a(b)² is said to be evaluated as (a×b)² then that's another way you can prove your good faith (When I say "explicit" I don't mean it must literally be that formula; the variables a and b could have different names, or could be constants written with numerals, and the exponent could be anything other than 1). Likewise, if you can find any explicit textbook example which specifically mentions an "exception" to the distributive law, that would demonstrate good faith.

I'm not saying that such an explicit example is the only way to demonstrate your claim, but I'm just trying to give you more opportunities to prove that you're not just a troll and that it's possible to have a productive discussion. You insist you're talking about mathematical rules that cannot be violated, so it should be no problem to find an explicit mention of them.

If you think this insistence on demonstrating your good faith is unfair, you should remember that you are saying that the practice of calculators, mathematical tools, programming languages and mathematical software are all wrong and that you are right, and that my interpretation of your own textbooks is wrong. While it's not impossible for many people to be wrong about something and for me to interpret something wrong, if you show no ability to admit error, or to admit that disagreement from competing authorities casts doubt on your claims, or to evince your controversial claims with explicit examples that are not subject to interpretational contortions, the likelihood is that you're not willing to ever see truth and there's no point arguing with such a person.

By the way, sorry for making multiple replies on the same point.

As my own show of good faith, I do see that one of your textbooks (Chrystal) has the convention that a number "carries with it" a + or -, which is suppressed in the case of a term-initial positive number. If you demonstrate it worth continuing the discussion, I'll explain why I think this is a bad convention and why the formal first-order language of arithmetic doesn't have this convention.

permalink

fedilink

source

parent

hideshow 3 child comments

[–] mindbleach@sh.itjust.works 1 point 10 months ago (2 children)

If you’ve written a(b)², then you mean (a×b)²

When shown a textbook that explicitly distinguishes 6(ab)^3^ meaning 6(ab)(ab)(ab) and (6ab)^3^ meaning (6ab)(6ab)(6ab), they accidentally got it right whilst sneering and inventing their sPeCiAl cAsE:

6a²b²=6(ab)²

They can't even keep their horseshit straight when their inane pivots to division are directly addressed. Every response begins "nuh uh!" and backfills whatever needs to be true for you to be wrong and them to be smarterer.

They're just full of shit.

permalink

fedilink

source

parent

hideshow 2 child comments

[–] FishFace@piefed.social 1 point 10 months ago (1 child)

I haven't been able to follow the entirety of that conversation so I don't remember what exactly he said about combining (implicit) multiplication, brackets and powers.

I think their fundamental confusion is in thinking that the distributive law is something you must do instead of a property of multiplication that you can use to aid in the manipulation of algebraic expressions but don't have to. Folded into their inability to understand that some aspects of maths are custom and convention, whilst others are rules fundamental to the operation of the universe. Somewhere along the way he seems to think that distributivity is something to do with brackets instead of something to do with addition and multiplication - I really don't understand how that has happened!

I'm pursuing a tack where I'll see if I can get him to actually cop to any of his verifiable mistakes, or back up any of his whackadoodle claims with direct references. If he can't, I'm out - but I do like to give people an opportunity to demonstrate they're not trolling. The nice thing is that it doesn't really matter whether they're trolling or not - someone who is able to admit mistakes is someone worth trying to convince they've made a mistake, and someone who isn't is not. So if you can test the waters with a simple mistake, even if it's not central, you can establish whether there's any point persevering.

Tomorrow I'm expecting another wall of text responding to every single word except the ones where I ask for such an admission, and I'll have satisfied myself he's a lost cause. I'll try and watch out for his spam on future arithmetic-ragebait threads so I can help the effort to head him off though :P

BTW did you go on his mastodon profile? He's had a bee in his bonnet about this, and been pushing his wrong ideas of what the distributive law are, since 2023.

permalink

fedilink

source

parent

hideshow 1 child comment

[–] mindbleach@sh.itjust.works 2 points 10 months ago*

Oh yeah, had a laugh at some RPN guy saying, 'Hey you should check this thesis specifically about order of operations.'

This dipshit: "I already know what it'll be - a University person who's forgotten about Terms and The Distributive Law - they're ALL like that."

All of them! Wow! What a coincidence!

Isn't it fucking crazy how everyone in the world is wrong about this, and math still works?

permalink

fedilink

source

parent

[–] mindbleach@sh.itjust.works 1 point 10 months ago (4 children)

So when you sneer that rules and notation are different, you don't know what those words mean.

Or you're so devoid of internality that when someone says 'imagine a different notation,' you literally can't.

There’s no pretending, It’s there in the textbooks

Show me any textbook that gets the answers you insist on. Show me one textbook where a(b+c)^2^ squares a.

permalink

fedilink

source

parent

hideshow 4 child comments

[–] SmartmanApps@programming.dev -1 points 10 months ago (2 children)

P.S. show me where the squared is in...

you know, the actual topic, which you're trying to avoid because you know you are wrong

permalink

fedilink

source

parent

hideshow 2 child comments

[–] mindbleach@sh.itjust.works 1 point 10 months ago (1 child)

Fuck where this started - you're here now, saying 2(8)^2^ is anything but 128. You're that wrong about basic fucking algebra, whilst sneering at everyone else.

Here's four textbooks across two centuries where a(b+c)^x^ is not (ac+bc)^x^.

permalink

fedilink

source

parent

hideshow 1 child comment

[–] SmartmanApps@programming.dev 0 points 10 months ago

Fuck where this started

I'll take that as an admission that you're wrong. Thanks for playing

permalink

fedilink

source

parent

[–] SmartmanApps@programming.dev -1 points 10 months ago

So when you sneer that rules and notation are different, you don’t know what those words mean

says the actual person who doesn't know what they mean 😂

when someone says ‘imagine a different notation,’ you literally can’t

Yes, you literally can't go rewriting all the rules of Maths that we've had for centuries just because you randomly want to do something different now that we've decided to add Brackets to it 😂 Your whole argument is based on pretending that all the rules of Maths were all written at the same time 🤣🤣🤣

Show me any textbook that gets the answers you insist on

Pick any of them which show a(b+c)=(ab+ac) 🙄

permalink

fedilink

source

parent

load more comments (1 reply)

[–] mindbleach@sh.itjust.works 0 points 10 months ago* (5 children)

your own textbook makes it clear that “doing brackets” means do what is inside the brackets first. Not what is outside the brackets.

Which this troll admits when sneering "They say you can [simplify first] when there is Addition or Subtraction inside the Brackets."

Except when they sneer you must not do that, because there's addition inside the brackets. 2(3*a+2*a)^2^ becomes 2(5*a)^2^, which gets a different answer, somehow. Or maybe it's 2(3a+2a)^2^ becoming 2(5a)^2^ that's different. One or the other is the SpEcIaL eXcEpTiOn to a rule they made up.

Weird how nobody else in the world has this problem. Almost like a convention that requires special cases is fucking stupid, and if people meant (2(n))^2^, they'd just write that.

Distributing 2 over a+b is not “doing brackets”; it is multiplication and comes afterwards.

Which this troll literally underlines when sneering about textbooks they don't read: "A number next to anything in brackets means the contents of the brackets should be multiplied."

Except when they insist distribution is totally different from multiplication... somehow. But if a product is one term and multiplying two things is a product and two things being multiplied is two terms, sure, fuck it, words don't mean things.

permalink

fedilink

source

parent

hideshow 5 child comments

[–] FishFace@piefed.social 0 points 10 months ago (4 children)

I actually forgot the most obvious way in which Order of Operations is a set of conventions... Some countries say "BODMAS" (division then multiplication) whilst others say "PEMDAS" (multiplication then division)...

permalink

fedilink

source

parent

hideshow 4 child comments

[–] mindbleach@sh.itjust.works 0 points 10 months ago (3 children)

They're grouped, being essentially the same operation, but inverted. Ditto for addition and subtraction. There's not a convenient word that covers both directions, like how exponents / order are the same for positive and negative powers.

Convention is saying 1/ab is 1/(ab) instead of (1/a)b, while 1/a*b is indeed (1/a)b. The latter of which this troll would say is a syntax error, because juxtaposition after brackets is foreboden... despite modern textbook examples.

permalink

fedilink

source

parent

hideshow 3 child comments

[–] FishFace@piefed.social 0 points 10 months ago* (2 children)

While reading some of his linked textbooks I found examples which define the solidus as operating on everything in the next term, which would have 1/ab = 1/(ab) = 1/(ab) = 1/ab. This is also how we were taught though as I recall it was not taught systematically: specifically I remember one teacher when I was about 17 complaining that people in her class were writing 1/a·b but should have been writing (1/a)·b (we generally used a dot for multiplication at this point). But at this point in our education, none of us remembered ever being taught this. I suspect what happened was that when being taught order of operations some years before, we simply never used the solidus and only used ÷ or fraction notation.

Anyway, if you have a correct understanding of what the order of operations really are (conventions) you can understand that these conventions all become a bit unwieldy when you have a very complex formula, and that it's better to write mathematics as if there were no such convention in those cases, and provide brackets for disambiguation. Thus while you might write ab ÷ bc and reasonably expect everyone to understand you mean (ab)/(bc) not ((ab)/b)c (which is what the strict interpretation of PEMDAS would say!) because "bc" just visually creates a single thing, the same is not true of the expression ab ÷ bc(x-1)(y-1)·sin(b), even though bc(x-1)(y-1)·sin(b) is a single term, and so the latter should be written more clearly.

Because DumbMan doesn't understand mathematical convention, he doesn't understand that these things really depend on how they're perceived, so is incapable of understanding such a way of working.

Anyway, looks like he's gone to sleep again now, I wonder if he'll pop up again in a couple of days, or if it'll take him until someone else posts some BODMAS clickbait.

permalink

fedilink

source

parent

hideshow 2 child comments

[–] mindbleach@sh.itjust.works 0 points 10 months ago (1 child)

Personally I tend to bracket aggressively, because I've been repeatedly betrayed by compilers. One in particular applied the high priority of & (bitwise and) to the low-priority && (logical and), so if( 1 < 2 && 3 ) would always fail because 2 && 3 evaluates to 1.

That was the topic the first time I dealt with this dingus and their rules of maths!!! about a year ago. The post was several months old. They've never understood that some things are fundamental... and some things are made up. Some things are mutable. So even if their nonsense was widespread, we could say, that's kinda stupid, we should do something else.

The dumbest argument I've ever suffered online was some dingdong convinced that "two times three" meant the quantity two, three times. Even though "two times" is right there, in the sentence. Even though "twice three" literally means "two times three." Even though the song "Three Times A Lady" obviously does not mean the quantity three, ladyce. Not even that dipshit thought two times three-squared could be thirty-six.

permalink

fedilink

source

parent

hideshow 1 child comment

[–] FishFace@piefed.social 2 points 10 months ago

Yeah, I'd make most stuff explicit in programming. You're rarely gonna do more than two arithmetic operations at a time anyways so you often get it for free. The most common one for me is % which I expect to bind weakly. I guess it binds tightly because it follows division, but I read "a + 1 % n" out loud with a "modulo" and when you say that in a mathematical context the modulo would apply to the entire expression to the left.

permalink

fedilink

source

parent

[–] mindbleach@sh.itjust.works 1 point 10 months ago (18 children)

b*c is the product of b and c.

Show me one textbook where a(b+c)^2^ gets an a^2^ term. Here's four in a row that say you're full of shit.

permalink

fedilink

source

parent

hideshow 18 child comments

[–] a comment that isn't shown here: deleted, from someone you've blocked, or on another page. view the thread from it

[–] mindbleach@sh.itjust.works 1 point 10 months ago (16 children)

The result of a multiplication operation is called a product.

Show me one textbook where a(b+c)^2^ gets an a^2^ term. Here's four in a row that say you're full of shit.

permalink

fedilink

source

parent

hideshow 16 child comments

[–] a comment that isn't shown here: deleted, from someone you've blocked, or on another page. view the thread from it

[–] mindbleach@sh.itjust.works 1 point 10 months ago* (last edited 10 months ago) (14 children)

Multiplying two things makes them one term.

"When a product involves a variable, it is customary to omit the symbol X of multiplication. Thus, 3 X n is written 3n and means three times n, and a X b is written ab and means a times b." Modern Algebra: Structure And Method, page 36. Immediately before the definition you're now lying about.

Fuck your non-sequitur. a(b+c)^2^ is a*(b+c)^2^, as backed up by - for example - these four math textbooks. No textbook will ever say it produces an a^2^ term. You made it up. You're just full of shit.

permalink

fedilink

source

parent

hideshow 14 child comments

[–] a comment that isn't shown here: deleted, from someone you've blocked, or on another page. view the thread from it

[–] mindbleach@sh.itjust.works 1 point 10 months ago* (12 children)

Yes... to make them one.

a*b and ab are both the product of a and b, and a product is one term. As explained by the textbook you chose.

a*b^2^ is ab^2^, even if b=(x+y). No textbook you're grasping for contains your made-up exception. They all show what I'm rubbing your nose in. You're just full of shit.

permalink

fedilink

source

parent

hideshow 12 child comments