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/sci/ - Science & Math

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2965228 No.2965228 [Reply] [Original]

Dear /sci/

Which group is right?

>> No.2965236

fuck off, had too many of those..

no.. it really isnt funny or anything...

>> No.2965234
File: 232 KB, 675x1000, 9_movie_poster.jpg [View same] [iqdb] [saucenao] [google]
2965234

>> No.2965238

Who the fuck uses that symbol for division? No one writes a formula that poorly, no wonder people are confused.

>> No.2965242

Words cannot describe how much I just do not care.

>> No.2965250

The answer is 9 if you never actually use math, 1 if you do.

>> No.2965254
File: 31 KB, 200x138, Alfred_Tarski_2.gif [View same] [iqdb] [saucenao] [google]
2965254

POLISH!!!!!

>> No.2965255

The answer is 9 if you went to a proper school, 1 if you went to an American one.

>> No.2965263

OP here.
The way I see it the answer is 1, since the 2 is part of the parenthetical statement and therefore must be resolved before we start dividing.

Why would it be 9?

>> No.2965268

>>2965263
Because 3 x 3 = 9.

>> No.2965271

>>2965263

Because technically the order of operations stipulates that multiplication and division are equal in rank and are done from left to right, which would make the expression 6/2(3) mean 6 divided by 2, multiplied by 3, which would yield 9.

>> No.2965272

>>2965268
If you resolve the parenthetical statement, it never gets to be 3x3.

>> No.2965274

>>2965263

6/2(1+2)
6/2(3)
3(3)
9

>> No.2965280

sage

>> No.2965282

>>2965274
You just divided while parentheses were still in the equation...

>> No.2965285

>>2965282

sorry, pretend the brackets aren't there

>> No.2965290

>>2965282
>>2965272
You already got your answer.

>> No.2965297
File: 31 KB, 633x529, wolfram.jpg [View same] [iqdb] [saucenao] [google]
2965297

Order of operations, multiplication and division have the same priority, solve whichever comes first left to right.
The parentheses is (1+2) nothing more, NOTHING MORE.
2(3) is a normal multiplication and follow the normal order of priority.
>6/2(1+2), solving the parentheses first gives:
>6/2(3), now we are left with one operation of division and one of multiplication, thus we do whichever comes first left to right, in this case then it is division
>3(3), now we just multiply
>9

pic related it is wolfram showing how the expression should be interpreted and the correct answer.

>> No.2965301

>>2965285
I don't even...
>>2965290
So I'm right?

>> No.2965302

<span class="math">6÷2(1+2)[/spoiler]
<span class="math">6\arccos{2\root 7\of{1+2}}^{\ln{12}}[/spoiler]

Implied functions everywhere!

>> No.2965303

There are no brackets around 2(1+2), implying it is meant to multiply the whole term 6/2 instead of the 2.

9 is correct.

We would get 1 if we had 6 OVER (2 multiplied by (1+2)), which is clearly not implicated by the equation since there are no brackets around those two terms. Thus we can also put (1+2) in front of the equation.

A good way to clearify this equation would be to, indeed, put (1+2) in front of the equation:

(1+2)*6/2 = 3*6/2 = 18/2 = 9

>> No.2965307

>>2965303
There are no brackets around 6÷2 either though, implying that 2(1+2) is one term and 6 is another.

>> No.2965311

>>2965307

That would be a quite fucked up way to write a fraction.

>> No.2965312

>>2965307

>There are no brackets around 6÷2 either though

Exactly.

<span class="math">6*2^{-1}(1+2)[/spoiler]

>> No.2965314
File: 48 KB, 470x600, 1233030445764.jpg [View same] [iqdb] [saucenao] [google]
2965314

>>2965228

>> No.2965316

>>2965307

it doesn't matter if it implies that (which it doesn't). as it's written, you've got to do the division first

>> No.2965317
File: 153 KB, 430x615, troll_trollercoaster.jpg [View same] [iqdb] [saucenao] [google]
2965317

>>2965228
catcha: I Fucked your mom

>> No.2965320

>>2965312
Alright, one last thing and you have me convinced then.
If 6÷2(1+2)= (6/2). And there's an implied 1 at brackets 1(1+2). Why doesn't 6÷(1+2) = 6*(1+2)?
Since 1 and 2 are both coefficients to (1+2).

>> No.2965333

Give on (accepted thorough the world) source saying you should go from left to right when calculating.

>> No.2965335

>>2965320

because <span class="math">6÷(1+2) = 6÷(1*(1+2)) \not= 6÷1*(1+2)[/spoiler]

÷ creates an inverse multiplicant until it encounters an equal or lower operation

>> No.2965352

>>2965335
>Equal or lower operation
>6÷2(1+2)
>Reaches end without meeting equal or lower.
>Therefore 6/(2(1+2)

>> No.2965358

6÷2(1+2)
6÷2(3)
3(3)
9

C grade GCSE mathematics education here so you know I am right.

>> No.2965360

>>2965352

Leaving the * is utterly faulty anyway, but assuming that a missing operation implies a * AND parenthesis for both factors leads to unnecessary complexion.

Same as in 6^2(1+2) != 6^(2*(1+2))

>> No.2965366

>>2965360
The * seems to be the root of this problem. Basically what I'm asking is why is it okay to separate the 2 from the parenthetical statement but not the 1?
If the question were 6÷1(1+2), would the answer be 18?
Where does it say you can separate the coefficient because it implies multiplication?

>> No.2965372

BoDMAS, much?

Evaluate the brackets first.

Also, the "6/2" term isn't multiplicitavely separate from the 1+2 term, i.e. the (1+2) bit is in the denominator, if it was "(6/2)", then it'd be 9.

It's 1, faggots.

>> No.2965381

>>2965333

None of you can ?

Trips are right then : there is no rule about it, so the expression is meaningless, so all OPs and those who reply either 1 or 9 are dumbtards

>> No.2965382

>>2965372
You're full of shit.

>> No.2965388

>>2965381
It's 9 either way.

>> No.2965387

>>2965366

Because there's an easy way to express 2(1+2) as a single term...

*drumroll*

(2(1+2)) !

Seriously, if I have the choice between one implication and 2 implications, I'll gladly take one.

>> No.2965400

>>2965381
Division and subtraction are just the multiplicative and additive inverse respectively. Frankly, you don't have to go left to right as long as you remember to convert it into an inverse before you continue. This discussion hasn't been about order for a while now...

>> No.2965401

>>2965381 failed GCSEs.

>> No.2965405

>>2965387
They both rely on only one implication...
Either the parentheses are around 6÷2 or around 2(1+2). The equation is poorly written, I'll agree with that, but I'm asking you to show me where it says that (6÷2) is more likely than (2(1+2)). My support is distributive property, what's yours?

>> No.2965410

>>2965387

Because there's an easy way to express 6/2 as a single term...

*drumroll*

(6/2) !

Seriously, if I have the choice between one implication and 2 implications, I'll gladly take one.

>> No.2965412

Furthermore:
>6÷2(1+2)
>x=1+2=3
6÷2x
>6=2*3
>6=2x
2x÷2x=1
Where did I preform and illegal action?

>> No.2965414

Please, learn to use the sage function, it's made for threads like this.
This has been posted here tens of times already in the past days.

>> No.2965427

>>2965405

You're wrong, 6÷2*(1+2) doesn't need any implied parenthesis, as it's equal to <span class="math">6*2^{-1}*(1+2)[/spoiler].

In the end it boils down to if you define a missing operation as a multiplication or as a multiplication AND parenthesis for its factors. The first assumes one implication, the second assumes two.
Or I could just assume that a missing operation in 2x means 2^sin(sqrt(x^3)).

>> No.2965433

>>2965412
not 2x its 2(x)

>> No.2965435

>>2965427
Alright, you'll win as soon as you answer this:
>>2965412

>> No.2965441

>>2965427
Yes it does it's 6/2(1+2) not (6/2)x(1+2)

>> No.2965443

>>2965433
In that case I concede that the answer is 9. I just needed to know why. Thanks /sci/.

>> No.2965442

>>2965435
refer to
>>2965433

>> No.2965448

>>2965441
Those are the same right one just has more shit in it.
That is exactly your problem, aside from trolling.
2*2 is the same as
(2)*(2)
and i could add even more like this: (((2)))*((2)) They all are the same.
6/2(1+2) = (6/2)x(1+2)

>> No.2965450

you cannot imply parentheses
you cannot imply parentheses
you cannot imply parentheses
you cannot imply parentheses
you cannot imply parentheses
you cannot imply parentheses
you cannot imply parentheses
you cannot imply parentheses
you cannot imply parentheses
you cannot imply parentheses

>> No.2965453
File: 27 KB, 350x468, 1298837345787.jpg [View same] [iqdb] [saucenao] [google]
2965453

>>2965435

Reading comprehension much?

6÷2(1+2)
2x÷2x or 2x÷2x

You assume:

(2*x)÷(2*x)

I assume:

2*x÷2*x which is equal to x*x


DO
NOT
FUCKING
IMPLY
PARENTHESES

>> No.2965454

>>2965443
That is how math works
You could be asking why 1+1 is 2

>> No.2965457

>>2965441
Now that is admirable. I applaud your internet maturity.

>>2965441
now you are not understanding the fact that the 2 is separate from the (1+2).

all together this was a poorly written equation, It's basically one of those stupid questions like "what's the safest form of sex? Not having sex!"

>> No.2965460

>>2965414
I assure you I was not trolling. I just wanted to get to the bottom of the matter, and none of my dumbass facebook friends managed to debate as well as OPisFAG5Y.

>> No.2965464

>>2965453
And that's why this is such an effective troll. You'd normally see that written as (2x) / (2x), and people are so used to seeing shit that way they auto-graft it onto this expression.

>> No.2965470

>>2965464

That and learning people arbitrary shit like mnemonics or acronyms without making them understand it.

>> No.2965471

>>2965412
You did it in the wrong order. You have 6÷2*x and you did the 2*x first. Division and multiplication have the same importance, so they're done from left to right. 6÷2 before 2*x. This leaves you with 3x, and since x=3, 9.

>> No.2965474

>>2965333
Because it's written left to right? We read left to right? I this like write don't sentences because meaning changed can easily pretty get.

6 / 2 * 3 is read as "six divided by two times three," not "six divided by the result of two times three."

>> No.2965480

>>2965471

I want to throw up every damn time I read this left-to-right shit.

6÷2*(1+2) = 6*(1÷2+2÷2)

Hurp durp I did it right to left.

>> No.2965484

>>2965450

THIS.

Fucking idiots.

It's not even in question that it is 9.

>> No.2965489

>>2965441

It's 6/2x(1+2) NOT 6/(2(1+2))

lrn2math

>> No.2965490

why is this even...?
go away trolls.

>> No.2965493

Whoever says the answer is 1 is a sick fuck and needs to go back to >>>/b/

>> No.2965494

>>2965490
OP here.
Read the whole thread. OPIsFAG5Y has convinced me, maybe he'll convince you. If not leave an intelligent complaint, or kindly fuck off. This is why I didn't ask people on FB, no substance.

>> No.2965499

>>2965470
>That and learning people arbitrary shit like mnemonics or acronyms without making them understand it.

One of the professors I work with (who mainly teaches remedial algebra) preaches GEMA instead of PEMDAS, where GEMA = Grouping, Exponents, Multiplication, Addition -- and division/subtraction are taught as inverses, so there there is no "Multiplication trumps Division because peMDas" or "Division takes priority because boDMas" ambiguity.

At first I thought it was kind of silly because PEMDAS was what I learned and it worked just fine for me, and I guess I figured that if they couldn't Order Of Operations they couldn't Inverse Functions either... but after seeing shit like this I can appreciate the wisdom.


This is still an unclear notation problem though, since interpretation ultimately comes down to what exactly is implied by 2(1+2). If it were written explicitly there'd be no troll here.

>> No.2965507

http://en.wikipedia.org/wiki/Multiplication#Notation_and_terminology

> multiplication involving variables is often written as a juxtaposition (e.g. xy for x times y or 5x for five times x). This notation can also be used for quantities that are surrounded by parentheses (e.g. 5(2) or (5)(2) for five times two).

It is 9

/thread

>> No.2965511

>>2965499

>since interpretation ultimately comes down to what exactly is implied by 2(1+2)

Exactly. And funnily enough, 80-90% of the math students and professors I've encountered imply a missing operation as both multiplication and parentheses.

When I ask them why they do it, it's usually a matter of being too lazy to write yet another pair of brackets.

Not that it'd matter in hand-written stuff, as it's usually clear through notation.

>> No.2965516

>>2965511

Little addition:

There IS in fact a problem I usually encounter in hand-written stuff:

sin2x

>> No.2965523

>>2965516
>sin2x
This has always bugged me with all of its relatives.

>> No.2965535

http://androidforums.com/2622443-post55.html

>> No.2965539

The group, that follows Jesus is right.

Jesus tells it is 9.

Praise the Lord.

>> No.2965545

the division sign is gay for this reason most of my professors will just mark it wrong if we use that however, if i remember from grade school with multiplication and division as well as addition and subtraction if there are no parentheses then then it should just be taken in the order shown, i think
so it should be 9