- Zellith ( @Zellith@kbin.social ) 74•7 months ago
watches the people with basic math skills fight to the death over the answer
- linuxdweeb ( @linuxdweeb@lemm.ee ) 40•7 months ago
Please Excuse My Dear Aunt Sally, she downloaded a shitty ad-infested calculator from the Google Play store.
- Empathy [he/him] ( @Empathy@beehaw.org ) 3•7 months ago
Unfortunately, it’s the best calculator I could find so far (for my own needs). I paid to remove the ads though, ads bother me way too much to use something infested with them.
- PM_ME_VINTAGE_30S [he/him] ( @PM_ME_VINTAGE_30S@lemmy.sdf.org ) English10•7 months ago
If you’re willing to pirate (or legally generate) a TI calculator ROM, then Graph 89 is probably what you’re looking for. This is what I use as my daily driver calculator with a TI-89 ROM.
- MilliaStrange ( @MilliaStrange@beehaw.org ) 1•7 months ago
Graph 89 with my TI-84 Plus Silver yields the bad answer
- shea ( @shea@lemmy.blahaj.zone ) 3•7 months ago
wabbitemu!!! Its literally a ti emulator
- subignition ( @subignition@kbin.social ) 34•7 months ago
[…] the question is ambiguous. There is no right or wrong if there are different conflicting rules. The only ones who claim that there is one rule are the ones which are wrong!
https://people.math.harvard.edu/~knill/pedagogy/ambiguity/index.html
As youngsters, math students are drilled in a particular
convention for the “order of operations,” which dictates the order thus:
parentheses, exponents, multiplication and division (to be treated
on equal footing, with ties broken by working from left to right), and
addition and subtraction (likewise of equal priority, with ties similarly
broken). Strict adherence to this elementary PEMDAS convention, I argued,
leads to only one answer: 16.Nonetheless, many readers (including my editor), equally adherent to what
they regarded as the standard order of operations, strenuously insisted
the right answer was 1. What was going on? After reading through the
many comments on the article, I realized most of these respondents were
using a different (and more sophisticated) convention than the elementary
PEMDAS convention I had described in the article.In this more sophisticated convention, which is often used in
algebra, implicit multiplication is given higher priority than explicit
multiplication or explicit division, in which those operations are written
explicitly with symbols like x * / or ÷. Under this more sophisticated
convention, the implicit multiplication in 2(2 + 2) is given higher
priority than the explicit division in 8÷2(2 + 2). In other words,
2(2+2) should be evaluated first. Doing so yields 8÷2(2 + 2) = 8÷8 = 1.
By the same rule, many commenters argued that the expression 8 ÷ 2(4)
was not synonymous with 8÷2x4, because the parentheses demanded immediate
resolution, thus giving 8÷8 = 1 again.This convention is very reasonable, and I agree that the answer is 1
if we adhere to it. But it is not universally adopted.- I_am_10_squirrels ( @I_am_10_squirrels@beehaw.org ) 2•7 months ago
Exactly, explicit multiplication is part of the parenthesis so it comes first in order of operations
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
[…] the question is ambiguous. There is no right or wrong if there are different conflicting rules. The only ones who claim that there is one rule are the ones which are wrong!
https://people.math.harvard.edu/~knill/pedagogy/ambiguity/index.html
Yeah nah. Actual Maths textbooks and proofs - did you not notice the complete lack of references to textbooks in the blog? It’s funny that he mentions Cajori though, given Cajori has a direct reference to Terms #MathsIsNeverAmbiguous
- subignition ( @subignition@kbin.social ) 1•3 months ago
I think I’m gonna trust someone from Harvard over your as-seen-on-TV looking ass account, but thanks for the entertainment you’ve provided by trying to argue with some of the actual mathematicians in here
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
I think I’m gonna trust someone from Harvard
So you’re going with the appeal to authority argument - ok, got it.
But if you’re gonna do that then make sure you check out Cajori’s credentials, since that’s, you know, who we both quoted.
argue with some of the actual mathematicians in here
You mean the dude who claimed to be, and was quoting wikipedia? BWAHAHAHAHA
- GTG3000 ( @GTG3000@programming.dev ) 23•7 months ago
I’m with the right answer here. / and * have same precedence and if you wanted to treat
2(2+2)
as a single unit, you should have written it like(2*(2+2))
.- sushibowl ( @sushibowl@feddit.nl ) 45•7 months ago
It’s pretty common even in academic literature to treat implied multiplication as having higher precedence than explicit multiplication/division. Otherwise an expression like 1 / 2n would have to be interpreted as (1 / 2) * n rather than the more natural 1 / (2 * n).
A lot of this bullshit can be avoided with better notation systems, but calculators tend to be limited in what you can write, so meh. Unless you want to mislead people for the memes, just put parentheses around things.
- GTG3000 ( @GTG3000@programming.dev ) 9•7 months ago
That’s fair. Personally, I just have a grudge against math notation in general. Makes my programmer brain hurt when there’s no consistency and a lot of implicit rules.
Then again, I also like Lisp so I’m not exactly without sin.
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
Makes my programmer brain hurt when there’s no consistency and a lot of implicit rules.
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
I’m with the right answer here
Apparently not.
if you wanted to treat 2(2+2) as a single unit
Yes, it is a Term subject to The Distributive Law, written just the way it is.
- Malgas ( @Malgas@beehaw.org ) English21•7 months ago
Left is correct; implicit multiplication takes precedence over explicit multiplication or division.
- 4am ( @4am@lemm.ee ) 3•7 months ago
What the fuck is the difference in implicit vs explicit? It’s the same operation, why the fuck does it matter if there is a symbol?
Multiplication comes first, then division.
- 0ops ( @0ops@lemm.ee ) 11•7 months ago
Division is a form of Multiplication, just as subtraction is a form of addition. You multiply and divide in the same step, left to right
- Malgas ( @Malgas@beehaw.org ) English8•7 months ago
No, multiplication and division are resolved from left to right in the same step. But implicit multiplication (
xy
, as opposed tox*y
) happens first. - 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
the difference in implicit vs explicit? It’s the same operation
“implicit multiplication” isn’t even a real thing in Maths, and isn’t even multiplication to begin with - people use that umbrella term to either mean The Distributive Law - which is the first step is solving Brackets - or Terms, which are products, which is the result of a multiplication.
e.g. if a=2 and b=3, then…
axb=2x3 - 2 terms
ab=6 - 1 term
Multiplication comes first, then division
They can be done in either order, or even together, as long as you go left to right.
- SimplyTadpole ( @SimplyTadpole@lemmy.dbzer0.com ) English1•7 months ago
What’s the difference between implicit multiplication and explicit multiplication?
- Malgas ( @Malgas@beehaw.org ) English6•7 months ago
Implicit multiplication is xy or x(y), explicit multiplication is x*y.
Basically just whether or not there’s an actual multiplication symbol.
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
Right idea, but wrong terminology.
There’s no such thing as implicit multiplication
xy is a Term - Terms are separated by operators (none in this case) and joined by grouping symbols.
x(y) is a Bracketed Term, and is therefore subject to The Distributive Law, which is the first step in solving Brackets.
And yes, a multiplication symbol is an operator - which therefore separates Terms (which is why ab and axb aren’t the same thing - it’s 1 term vs. 2 terms), and the “M” in the mnemonics refers literally to multiplication signs, and nothing else.
- arisunz ( @arisunz@lemmy.blahaj.zone ) 19•7 months ago
this comment section illustrates perfectly why i hate maths so much lmao
love ambiguous, confusing rules nobody can even agree on!
- onion ( @onion@feddit.de ) 23•7 months ago
The problem isn’t math, it’s the people that suck at at it who write ambigous terms like this, and all the people in the comments who weren’t educated properly on what conventions are.
- Swallowtail ( @Swallowtail@beehaw.org ) 5•7 months ago
Yeah, you could easily make this more straightforward by putting parentheses around 8÷2. It’s like saying literature sucks because Finnegans Wake is incomprehensible.
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
you could easily make this more straightforward by putting parentheses around 8÷2
But that would be a different expression with a different answer (16 rather than 1). This is the mistake made by the programmer of the e-calc - treats it as though there’s extra brackets there when there isn’t.
- loops ( @loops@beehaw.org ) English3•7 months ago
Huge shout out to the jaded AF high school math teachers that don’t give a fuck any more!
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
They do care. The issue is everyone argues about it without even asking Maths teachers about it to being with! I guarantee (I’ve seen it myself) literally every blog you read which says this is “ambiguous”, without exception they never mention Maths textbooks or Maths teachers (because then they wouldn’t be able to bombastically declare “This is ambiguous!”).
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
write ambigous terms like this
It’s not ambiguous
all the people in the comments who weren’t educated properly on what conventions are
Everyone was taught the rules of Maths - it’s just a matter of who remembers them or not.
- 4am ( @4am@lemm.ee ) 7•7 months ago
PEMDAS
Parenthesis, exponents, multiplication, division, addition, subtraction.
The rule is much older than me and they taught it in school. Nothing ambiguous about it, homie. The phone app is fucked up. Calculator nailed it.
- hallettj ( @hallettj@beehaw.org ) English7•7 months ago
The comment from subignition explains that the phone’s answer, 16, is what you get by strictly following PEMDAS: the rule is that multiplication and division have the same precedence, and you evaluate them from left-to-right.
The calculator uses a different convention where either multiplication has higher priority than division, or where “implicit” multiplication has higher priority (where there is no multiply sign between adjacent expressions).
- I_am_10_squirrels ( @I_am_10_squirrels@beehaw.org ) 2•7 months ago
But explicit multiplication is part of the parenthesis, so still comes before division or exponent
- hallettj ( @hallettj@beehaw.org ) English3•7 months ago
The parentheses step only covers expressions inside parentheses. That’s 2 + 2 in this case. The times-2 part is outside the parentheses so it’s evaluated in a different step.
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
The parentheses step only covers expressions inside parentheses
No, it doesn’t
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
16, is what you get by strictly following PEMDAS
except 1 is what you get from strictly following PEMDAS. If you got 16 then you missed one of more rules.
the rule is that multiplication and division have the same precedence, and you evaluate them from left-to-right
Go back and read your link again. You’ll find they’re obeying The Distributive Law. i.e. solve all brackets first, from inner-most out.
“implicit” multiplication
- arisunz ( @arisunz@lemmy.blahaj.zone ) 2•7 months ago
i know about pemdas and also my brother in christ half the people in the comments are saying the phone app is right lmao
edit: my first answer was 16
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
rules nobody can even agree on!
All the Maths textbooks agree
- I Cast Fist ( @ICastFist@programming.dev ) English17•7 months ago
The problem is that there’s no “external” parentheses to really tell us which is right:
(8 / 2) * 4
or8 / (2 * 4)
The amount of comments here shows how much debate this “simple” thing generates
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
The problem is that there’s no “external” parentheses to really tell us which is right: (8 / 2) * 4 or 8 / (2 * 4)
The Distributive Law tells us it’s the latter.
- Dynamo ( @dynamo@lemm.ee ) 16•7 months ago
16
- MystikIncarnate ( @MystikIncarnate@lemmy.ca ) English15•7 months ago
People in this thread need to watch this: https://youtu.be/lLCDca6dYpA
- GrimChaos ( @GrimChaos@lemm.ee ) 3•7 months ago
And the much longer video by the same person:
Problem with PEMDAS: Why Calculators Disagree https://youtu.be/4x-BcYCiKCk
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
Problem with PEMDAS: Why Calculators Disagree https://youtu.be/4x-BcYCiKCk
Debunked here - she never once refers to an actual Maths textbook!
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
People in this thread need to watch this: https://youtu.be/lLCDca6dYpA
Debunked here. She managed to never once refer to an actual Maths textbook! Spoiler alert: everyone who has claimed it’s “ambiguous” has done the same thing - no references to any Maths textbooks.
- MystikIncarnate ( @MystikIncarnate@lemmy.ca ) English1•3 months ago
If you think I’m navigating that mess of cross linked posts, well, you’re in for a surprise.
You’re really late to this thread.
She didn’t reference any math textbooks because she made the video for commoners, aka not math majors. Her explanations make sense even if they’re technically wrong from the perspective of pure mathematics.
Unfortunately, I don’t think many people are going to see your reply, and fewer still will deal with the format you’ve chosen to present it in; an even smaller subset will likely understand the concepts you’re trying to explain.
Unfortunately, posting this, so long after the thread was active, linking to your own social media as a reference, seems a lot more like attention seeking behavior. The kind of thing I would expect from a bot or phishing attack, especially since you seem to have copy/pasted the reply on several comments. It’s like you searched for the YouTube link and just vomitted the same reply on every reference to it. That’s bot behavior.
I’m not saying you’re actually a bot, or that anything you’ve posted is incorrect at all. It just seems suspect.
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
you’re in for a surprise
I’m not actually. A lot of people don’t want to confront evidence that they’re wrong.
She didn’t reference any math textbooks because she made the video for commoners, aka not math majors.
Did you notice she’s a Physics major? In other words, she doesn’t have any Maths textbooks to reference.
Her explanations make sense
So, even when she couldn’t explain why one calculator “sometimes obeys juxtaposition, sometimes doesn’t”, that still made sense to you?
technically wrong
Bingo!
I don’t think many people are going to see your reply
These comments are going to show up in search results for the rest of eternity, so I’m quite happy to debunk the disinformation in it.
you seem to have copy/pasted the reply on several comments
3 different people referred to the same video, so yeah I did something I don’t normally do and copy/pasted for those 3 people. Read my other replies and you’ll find they’re all specific to the person I’m replying to.
It’s like you searched for the YouTube link
No, I’ve had multiple people tell me about it previously, as “proof” that Maths is ambiguous, hence why I wrote a thread debunking the claims she (and others) made.
It just seems suspect
It’s all legit, so feel free to go back and read what I’ve written given that context.
- JeffKerman1999 ( @JeffKerman1999@sopuli.xyz ) 1•7 months ago
I couldn’t listen, voice way too off-putting
- Slovene ( @Slovene@feddit.nl ) 1•7 months ago
Really?! I find her voice incredibly sexy.
- JeffKerman1999 ( @JeffKerman1999@sopuli.xyz ) 1•7 months ago
Yeah to me it sounds ultra fake try hard
- Queue ( @queue@lemmy.blahaj.zone ) English13•3 months ago
For anyone like me who has math as their worst subject: PEMDAS.
PEMDAS is an acronym used to mention the order of operations to be followed while solving expressions having multiple operations. PEMDAS stands for P- Parentheses, E- Exponents, M- Multiplication, D- Division, A- Addition, and S- Subtraction.
So we gotta do it in the proper order. And remember, if the number is written like
2(3)
then its multiplication, as if it was written2 x 3
or2 * 3
.So we read
8/2(2+2)
and need to do the following;- Read the Parentheses of
(2 + 2)
and follow the order of operations within them, which gets us 4. - Then we do
2(4)
which is the same as2 x 4
which is8
8 / 8
is1
.
The answer is 1. The old calculator is correct, the phone app which has ads backed into it for a thing that all computers were invented to do is inaccurate.
- nutcase2690 ( @nutcase2690@lemmy.dbzer0.com ) 7•7 months ago
The problem with this is that the division symbol is not an accurate representation of the intended meaning. Division is usually written in fractions which has an implied set of parenthesis, and is the same priority as multiplication. This is because dividing by a number is the same as multiplying by the inverse, same as subtracting is adding the negative of a number.
8/2(2+2) could be rewritten as 8×1/2×(2+2) or (8×(2+2))/2 which both resolve into 16.
- Zagorath ( @Zagorath@aussie.zone ) 7•7 months ago
You left out the way it can be rewritten which most mathematicians would actually use, which is 8/(2(2+2)), which resolves to 1.
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
Division is usually written in fractions
Division and fractions aren’t the same thing.
fractions which has an implied set of parenthesis
Fractions are explicitly Terms. Terms are separated by operators (such as division) and joined by grouping symbols (such as a fraction bar), so 1÷2 is 2 terms, but ½ is 1 term.
8/2(2+2) could be rewritten as 8×1/2×(2+2)
No, it can’t. 2(2+2) is 1 term, in the denominator. When you added the multiply you broke it into 2 terms, and sent the (2+2) into the numerator, thus leading to a different answer. 8/2(2+2)=1.
- hallettj ( @hallettj@beehaw.org ) English2•7 months ago
The problem is that the way PEMDAS is usually taught multiplication and division are supposed to have equal precedence. The acronym makes it look like multiplication comes before division, but you’re supposed to read MD and as one step. (The same goes for addition and subtraction so AS is also supposed to be one step.) It this example the division is left of the multiplication so because they have equal precedence (according to PEMDAS) the division applies first.
IMO it’s bad acronym design. It would be easier if multiplication did come before division because that is how everyone intuitively reads the acronym.
Maybe it should be PE(M/D)(A/S). But that version is tricky to pronounce. Or maybe there shouldn’t be an acronym at all.
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
but you’re supposed to read MD and as one step
You can do them in any order at all - M then D, D then M (hence the acronym BEDMAS), or all in one - what does matter is not treating Distribution as though it’s Multiplication (which refers literally to multiplication signs), when in actual fact it’s the first step in solving Brackets.
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
Turns out I’m wrong, but I haven’t been told how or why. I’m willing to learn if people actually tell me
Well, I don’t know what you said originally, so I don’t know what it is you were told was wrong - 1 or 16? 😂 The correct answer is 1.
Anyhow, I have an order of operations thread which covers literally everything there is to know about it (including covering all the common mistakes and false claims made by some). It includes textbook references, historical Maths documents, worked examples, proofs, memes, the works! I’m a high school Maths teacher/tutor - I’ve taught this topic many times.
- SimplyTadpole ( @SimplyTadpole@lemmy.dbzer0.com ) English1•7 months ago
You’re a lifesaver, thank you so much. I actually didn’t know about PEMDAS, I was never taught it before…
- Read the Parentheses of
- hallettj ( @hallettj@beehaw.org ) English11•7 months ago
This is exactly why we have Reversed Polish Notation. When will people learn?
- millie ( @millie@slrpnk.net ) 3•7 months ago
A fifteen year old version of myself somewhere inside just screamed in iptscrae induced frustration.
- groucho ( @groucho@lemmy.sdf.org ) English2•7 months ago
RPN Gang unite!
- Another Catgirl ( @anothercatgirl@lemmy.blahaj.zone ) English8•7 months ago
there’s a setting in Qalculate! that asks if you want implicit multiplication to apply to the denominator or the numerator
- cRazi_man ( @cRazi_man@lemm.ee ) 5•7 months ago
Ah damn it. It took me ages to find a calculator app that fits my needs… And now I find out it works like the one on the right.
- Razzazzika ( @Razzazzika@lemm.ee ) 8•7 months ago
… the one on the right is correct… that’s a jank ass calculator on the left that doesn’t know how to do order of operations 8/2×(2+2) 8/2x4 4x4 16
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
the one on the right is correct
No, it isn’t.
8/2×(2+2)
…isn’t the same thing as 8/2(2+2). You separated the term in the denominator, leading the (2+2) to get flipped into the numerator, hence wrong answer.
- Razzazzika ( @Razzazzika@lemm.ee ) 1•3 months ago
That would be 8/(2x(2+2)) if we were keeping it all in the denominator. Multiplication happens in the numerator if there are no parenthesis to distinguish it. If thr equation was written like this:
8
2x(2+2)
Then you would also be correct, but I have to respectfully disagree with your analysis.
- 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱 ( @SmartmanApps@programming.dev ) English1•3 months ago
That would be 8/(2x(2+2)) if we were keeping it all in the denominator
(2x(2+2)) is the same thing as 2(2+2)
I have to respectfully disagree with your analysis
Which means you disagree with how Maths textbooks teach how to do this (see previous link).
- sunbather ( @sunbather@beehaw.org ) 5•7 months ago
8÷2(2+2)=2(2+2)÷2(2+2)
alternatively if 8÷2(2+2)=16 that means 2(2+2)=8÷16 in other words 8=0,5 which it isnt
- rasensprenger ( @rasensprenger@feddit.de ) 9•7 months ago
your first line is correct, but while it looks like 1 (and it might be under different conventions), evaluating according to standard rules (left to right if not disambiguated by pemdas) yields
2(2+2)/2(2+2) = 2(4)/2(4) = 2*4/2*4 = 8/2*4 = 4*4 = 16
Using implicit multiplication in quotients is weird and really shouldn’t happen, this would usually be written as 8/(2*(2+2)) or 8/2*(2+2) and both are much clearer
Your second argument only works if you treat 2(2+2) as a single “thing”, which it looks like, but isn’t, in this case
- sunbather ( @sunbather@beehaw.org ) 3•7 months ago
not much to refute in the argument of whether its 16 or 1 as its all a matter of convention in the end and ultimately the root of the argument is poor formatting of the expression, im used to implicit multiplication taking precedent and that 2(2+2)===2*(2+2) and that for my first argument having the same expression on 2 sides of a division sign automatically equals 1, but how come you find implicit multiplication in quotients weird? seeing as it happens literally all the time in equations, unless thats a difference in school systems or similar im unaware of
for fun also rewrote the expression into powers of 2 and indeed depending on how you go about implicit multiplication i end up with either 2⁰ or 2⁴, so for the sake of sanity i figure its best to just say x₁=1; x₂=16
- rasensprenger ( @rasensprenger@feddit.de ) 3•7 months ago
It’s weird because usually the people writing the expressions want to communicate clearly, and stuff like 1/2x is not immediately clear to everyone, so they write the 1/2 as a fraction.
The same expression on both sides of the division sign only reduce to one if they actually bind to the division sign, which is rarely an issue, but that is exactly the thing that is in question here. I think it’s clear that 1 + 1/1 + 1 is 3, not 1, even though 1+1 = 1+1.
But as you said, of course, the evaluation order is just convention, you can just as well write everything in https://en.m.wikipedia.org/wiki/Reverse_Polish_notation
- Limitless_screaming ( @Limitless_screaming@kbin.social ) 5•7 months ago
I don’t think you encounter this one very often, but the technically correct
-2^2 = -4
has a higher chance of ruining your day.- hallettj ( @hallettj@beehaw.org ) English1•7 months ago
Oh goddammit! Why doesn’t PEMDAS prepare us for unary negation??
- onion ( @onion@feddit.de ) 1•7 months ago
You mean x^2 =4 where x=±2
- Limitless_screaming ( @Limitless_screaming@kbin.social ) 2•7 months ago
No, you’d expect that -2^2 would equal 4, but calculators solve it as -(2)^2 not (-2)^2. But the case you mentioned is also pretty common.
- 0ops ( @0ops@lemm.ee ) 3•7 months ago
I think they mean that you said the correct answer is -8 in your first comment. Typo?
- Limitless_screaming ( @Limitless_screaming@kbin.social ) 1•7 months ago
I was taught that negative numbers should be written as (-2) with the parentheses when using exponents. So I assume that the calculators are doing it right, or maybe it’s just a measure against calculators doing it wrong? I cannot be sure. Also
-2 = 0-2
so-2^2 = 0-2^2
.- 0ops ( @0ops@lemm.ee ) 1•7 months ago
No you misunderstand. I’m not talking about the negative. 2² = 4. But in your original comment you said -2² = -8 ? I think you meant -2² = -4
- Limitless_screaming ( @Limitless_screaming@kbin.social ) 1•7 months ago
Oh, right. It should have been -4. Thanks.
- 0ops ( @0ops@lemm.ee ) 1•7 months ago
No big
- onion ( @onion@feddit.de ) 1•7 months ago
My calculators have a separate sign button labeled “(–)”
- Limitless_screaming ( @Limitless_screaming@kbin.social ) 1•7 months ago
Mine have it too, but it doesn’t change the results.