6Γ·2(1+2)
π‘πππΊππππΊπ π°ππππ± @ SmartmanApps @programming.dev Posts 22Comments 591Joined 2 yr. ago
π‘πππΊππππΊπ π°ππππ± @ SmartmanApps @programming.dev
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6 / 2 * 3 into 6 * 3 / 2 (note that I moved the division with the 2)
And note that it doesn't work if the multiply was an addition. e.g. 6/2+3=6 but 6+3/2=7.5. Multiplication and division are both binary operators, and you can't move them around unless you also move the term to the left with it. i.e. 6/2+3=6. 3+6/2=6.
Just remember that left to the six is an βimaginaryβ (donβt quote me ^^) multiplication
No, to the left of the 6 is an actual plus sign, but we don't write plus signs if it's at the start of an expression. +6 and x6 aren't the same thing at all (and, since x is a binary operator, you couldn't write just x6 anyway - there would have to be a term to it's left). No expression ever starts with x6.
Thatβs not really possible with multiplication because β/2β is not a valid notation for β1/2β
It's not a valid notation for multiplication either - both multiplication and division are binary operators and must be written with 2 terms.
Semi-related: something in me wants to read that as 6 / (2*3)
100% related actually, since that's the actual next line of working out. i.e. you cannot remove brackets unless there is only 1 term left inside, a mistake which those who have prematurely removed brackets have made and ended up with the wrong answer (because it flips the 3 from being in the denominator to being in the numerator).
if you feel that itβs your personal mission to generate traffic for a particular channel on a lemmy instance
Oh! One last fact check on your false claims - I don't even post on 1 instance! P.S. take note of the upvotes.
dead, as it was expected to be
Ah! Now I see why you're attacking - trying to prove you were "right". You weren't, you were wrong.
if they filter out your personal
...it'll still be 35 users/month, which is still not dead.
itβs your personal mission to generate traffic
I'm not generating the other 34 people who used it this month, which includes, as I mentioned before, someone who actually provided me with a solution to a problem I had. Welcome to why Communities are useful. Not sure what purpose you think they're for?
Itβs ok if you feel that itβs your personal mission
As opposed to your apparent personal mission of trying to declare groups dead which actually aren't?
Bye now Mr. Gaslighter.
Iβm sorry, youβre trying to blatantly lie with statistics.
No, you're lying by using a different definition of "dead". See screenshot I already posted. It comes from this very Community. It's based on how many monthly users there are, not how many posts there are. BTW the number of users has gone up since you made your previous comment - the MAUI community now on 35 users a month (only 1 of them is me), which is well on the way to being classified as "moderate" rather than just "quiet". Sorry to break it to you, but you're still wrong. As I said, take your gaslighting elsewhere.
when you read a paper that contains math, you wonβt see a declaration about what countryβs notation is used for things that arenβt defined
Not hard to work out. It'll be , for decimal point and : for division, or . for decimal point and Γ· or / for division, and those 2 notations never get mixed with each other, so never any ambiguity about which it is. The question here is using Γ· so there's no ambiguity about what that means - it's a division operator (and being an operator, it is separating the terms).
Probably a cop-out from the teacher
No, that's an actual convention of Maths, to make sure people (who don't know better) obey the actual rule of left associativity.
Neither is ambiguous. #MathsIsNeverAmbiguous ab=(axb) by definition. Here it is referred to in Cajori nearly 100 years ago (1928), and literally every textbook example quoted by Lennes (1917) follows the same definition, as do all modern textbooks. Did you not notice that the blog didn't refer to any Maths textbooks? Nor asked any Maths teachers about it.
you canβt prove that some notation is correct and an alternative one isnβt
I never said any of it wasn't correct. It's all correct, just depends on what notation is used in your country as to what's correct in your country.
Itβs all just convention.
No, it's all defined. In Australia we use the obelus, which by definition is division. In European countries they use colon, which by definition in those countries means division. 1+1=2 by definition. If you wanna say 1+1=2 is just a convention then you don't understand how Maths works at all.
What you are saying is like saying "there's no such things as dictionaries, there are no definitions, only conventions".
Maths is pure logic. Notation is communication, which isnβt necessarily super logical. Donβt mix the two up.
Don't mix up super logical Maths notation with "communication" - it's all defined (just like words which are used to communicate are defined in a dictionary, except Maths definitions don't evolve - we can see the same definitions being used more than 100 years ago. See Lennes' letter).
Yep, that's the "quote" in the blog, but if you click on the link not only is it not on page 21, it's not in there at all. i.e. the quote - if it even is a quote - is out of context.
It was incredibly thorough and well researched
It never mentions the 2 relevant rules of Maths, nor any textbooks, nor speaks to any Maths teachers. You can find all those thing here
Iβm not a mathematician and the answer is 9
I'm a Mathematician and the answer is 1.
I donβt agree with the notation of the American Physical Society
I clicked on the link to see what you were talking about, and the quotes which are used in the blog aren't in there at all. i.e. I searched the whole document, not just the referenced page, and, for example, the expression "multiplication before division" isn't in there at all. On the other hand the stuff about not inserting multiplication signs into terms is 100% correct, because you are breaking up one term into two, and dropping the precedence from Terms to Multiplication, which changes the answer.
Look, this is not the only case where semantics and syntax donβt always map
Syntax varies, semantics doesn't. e.g. in some places colon is used for division, in others an obelus, but regardless of which notation you use, the interpretation of division is immutable.
they use different semantics for a notation that for you seems to have clear meaning
They might use different notation, but the semantics is universal.
You need to accept that human communication isnβt as perfectly unambiguous as mathematics (writing math down using notation is a way of communicating)
Writing Maths notation is a way of using Maths, and has to be interpreted according to the rules of Maths - that's what they exist for!
if it was 6Γ·2x(2+1) they suggested do division and mult from left to right, but 6Γ·2(2+1)
Correct! Terms are separated by operators and joined by grouping symbols, so 6Γ·2x(2+1) is 3 terms - 6, 2, and (2+1) - whereas 6Γ·2(2+1) is 2 terms - 6 and 2(2+1), and the latter term has a precedence of "brackets", NOT "multiplication". Multiplication refers literally to multiplication signs, which are only present in your first example (hence evaluated with a different order than your second example).
Also noted that the OP has ignored your comment, seeing as how you pointed out the unambiguous way to do it.
implicit multiplication
There's no such thing as "implicit multiplication"
Some place it above explicit multiplication and division,
Which is correct, seeing as how we're solving brackets, and brackets always come first.
But if you place it as equal to itβs explicit counterparts, then youβd sweep left to right giving you an answer of 9
Which is wrong.
Since those are both valid interpretations of the order of operations
No, they're not. Treating brackets as, you know, brackets, is the only valid interpretation. "Multiplication" refers literally to multiplication signs, of which there are none in this problem.
But in reality nobody would write an equation like this
Yes they would. a(b+c) is the standard way to write a factorised term.
6β2(1+2) β 6β2*3 β 6β6 β 1
You're more patient than me to go to that trouble! π But yeah, looks good. Just one technicality (and relates to how many people arrive at the wrong answer), the 2x3 should be in brackets. Yes if you had a proper fraction bar it wouldn't matter, but that's what's missing with inline writing, and is compensated for with brackets (and brackets can't be removed unless there's only 1 term inside). In your original comment, it does indeed look like 6/(2x3), but, to illustrate the issue with what you wrote, as soon as I quoted it, it now looks like (6/2)x3 in my comment.
There's only 1 set of rules, and 2 sets of people - those who follow the rules and those who don't.