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im pretty sure i got thrown off by the ÷ lol. i pretty much never read divide like that.. always as / instead. i wouldnt be surprised if that caused my brain to immediately group left and right side, making 2, because i dunno.. maybe i brain didnt see the usual / symbol and though addition or something for the ordering. kinda interesting though.
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Not sure what the point of the second question. Usually if it's on the same line in a real math problem is (1/2)x and if it's 1/(2x) it'll be on a seperate line.
1 1
-- vs -- x or 1/2x
2x 2
Of course I too want to group it as 1/(2x) but in really computer symbol " / " is inadequately designed for dividing.
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On April 08 2011 07:56 Mailing wrote:Show nested quote +On April 08 2011 07:55 Zeke50100 wrote:On April 08 2011 07:52 Mailing wrote:Holy shit, even the internet doesn't know o_o ![[image loading]](http://imgur.com/HvN5t.jpg) When written in a single line, it's interpreted just the way it's supposed to be, which is 288. You cannot change the formatting of the problem to what the image says, because that essentially sticks parentheses around areas that SHOULDN'T. The real problem is that people confuse single-line math with handwritten math, and how one translates exactly in to another. In single-line math, fractions with more than a single term in either the numerator or denominator exist only when parenthesis "block" them off. I did not change it, the computer changed 48÷2(9+3) to the first format itself...
Yeah, sorry, I misinterpreted what you wrote. I edited my post accordingly. My bad!
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On April 08 2011 07:53 MandoRelease wrote:Show nested quote +On April 08 2011 07:10 mikeymoo wrote:
It really depends on the context. You would never see a formula typed out linearly like this in any paper.
It's like reading "cos2x" and arguing that technically it should be equal to cos(2)*x when most people would see cos(2x). I made an assumption about the equation because it's being asked in the first place. Most arithmetically sound people wouldn't ask this question on a forum, so I assumed that the author was bad at math. Someone bad at math would definitely phrase this question as something he/she had seen on his/her homework, that is, they would write 48/(2(9+3)) as seen on homework as what was typed in the poll.
Yes, it's technically 288. Usually if it is meant to evaluate to 288, it would be written (48/2)(9+3), for clarity. I'm not embarrassed at all to have answered 2. I strongly disagree with the bolded part. Math does not depend on the context. The poll asked for the answer of the calcul (computation ? I don't know what word to use sorry), and the calcul was crystal clear since omitting the mutltiplicative sign here is perfectly correct. However omitting the parentheses in "cos2x" is not, and has never been written as such in any accurate paper/article/book i've read. I don't believe your comparison is correct.
The omission of parentheses in the context of trigonometric functions is made all the time, actually.
There are more things in heaven and earth than exist in your philosophy, I guess.
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I do get the answers and arguments for each.
However ÷ is also used as an oldschool minus (-).
Therefore the result could just as well be:
48-(2*(9+3)) = 48-2(9+3)= 24.
I would even argue that it would be the most obvious answer to the equation given the lack of attempts to avoid misinterpretation by the auther!
As for the poll, I vote "none of the above" i.e. I don't vote because no answers fits my interpretation!
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On April 08 2011 07:58 munchmunch wrote:Show nested quote +On April 08 2011 07:53 MandoRelease wrote:On April 08 2011 07:10 mikeymoo wrote:
It really depends on the context. You would never see a formula typed out linearly like this in any paper.
It's like reading "cos2x" and arguing that technically it should be equal to cos(2)*x when most people would see cos(2x). I made an assumption about the equation because it's being asked in the first place. Most arithmetically sound people wouldn't ask this question on a forum, so I assumed that the author was bad at math. Someone bad at math would definitely phrase this question as something he/she had seen on his/her homework, that is, they would write 48/(2(9+3)) as seen on homework as what was typed in the poll.
Yes, it's technically 288. Usually if it is meant to evaluate to 288, it would be written (48/2)(9+3), for clarity. I'm not embarrassed at all to have answered 2. I strongly disagree with the bolded part. Math does not depend on the context. The poll asked for the answer of the calcul (computation ? I don't know what word to use sorry), and the calcul was crystal clear since omitting the mutltiplicative sign here is perfectly correct. However omitting the parentheses in "cos2x" is not, and has never been written as such in any accurate paper/article/book i've read. I don't believe your comparison is correct. The omission of parentheses is made all the time, actually.
That's due to laziness, rather than because people believing it's correct. The problem is that people who DO now how to write it "pass on" the incorrect way to do it, creating quite a bit of confusion when it comes to mathematical form >.>
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Another way to put my last point: properly understood, PEMDAS is a disambiguation procedure. Don't confuse the availability of a disambiguation procedure with a lack of ambiguity.
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On April 08 2011 07:53 Chimpalimp wrote:
The reason most people got the first one wrong is that they assume that multiplication has precedence over divison, which is incorrect.
PEMDAS
The order of precedence occurs as such:
1. Parenthesis
2. Exponent
3. Multiplication = Division
4. Addition = Subtraction
When given the case that there are two operations which have equal precedence, always do the first one. This is the reason the correct answer is 288 and not 2.
The same holds true for problem 2:
the answer is (1/2)*x not 1/(2*x), because the division comes before the multiplication.
Not to insult anyone but if they write 1/2x to mean 1/(2*x), they are just being lazy with their notation. Any of my professors would count my answer wrong if I wrote 1/2x to mean 1/(2*x).
You won't imagine how much time I spent trying to figure out what PEMDAS was >_> Pretty much took me from page 1 'till here...
EDIT: In DK we call it basic math
EDIT2: my first edit made me arrogant, that wasn't the intention - it really is what we call it...
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Here's a super easy math problem:
Poll: Cos((pi)/2) = ?0 (19) 73% (ipsoC)/2 (7) 27% 26 total votes Your vote: Cos((pi)/2) = ? (Vote): 0
(Vote): (ipsoC)/2
If you get it wrong your IQ is under 3 but greater than 4. And by that I mean, if you think one is wrong because of "technicalities" you learned in an arithmetic class in 7th grade, you lose. It's notation, what is right is the idea, but how we write the idea is just convention...
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On April 08 2011 07:53 MandoRelease wrote:
However omitting the parentheses in "cos2x" is not, and has never been written as such in any accurate paper/article/book i've read. I don't believe your comparison is correct.
And you would believe anyone would write the expression in the OP in any accurate paper/article/book? It would never make it into print unless it's presented as an example of purposely misleading notation.
edit: @ Rackdude: Clearly that's cosh(p/2)
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2x has a different order than 2*x. 2x is treated as a single unit in all scientific disciplines. The answer is 2. If the equation were 48/2*(9+3) the answer would be 288.
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On April 08 2011 07:57 Steel wrote:
Not sure what the point of the second question. Usually if it's on the same line in a real math problem is (1/2)x and if it's 1/(2x) it'll be on a seperate line.
1 1
-- vs -- x or 1/2x
2x 2
Of course I too want to group it as 1/(2x) but in really computer symbol " / " is inadequately designed for dividing.
Or for god's sake, just write 0.5x
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On April 08 2011 08:00 Ghostcom wrote:Show nested quote +On April 08 2011 07:53 Chimpalimp wrote:
The reason most people got the first one wrong is that they assume that multiplication has precedence over divison, which is incorrect.
PEMDAS
The order of precedence occurs as such:
1. Parenthesis
2. Exponent
3. Multiplication = Division
4. Addition = Subtraction
When given the case that there are two operations which have equal precedence, always do the first one. This is the reason the correct answer is 288 and not 2.
The same holds true for problem 2:
the answer is (1/2)*x not 1/(2*x), because the division comes before the multiplication.
Not to insult anyone but if they write 1/2x to mean 1/(2*x), they are just being lazy with their notation. Any of my professors would count my answer wrong if I wrote 1/2x to mean 1/(2*x). You won't imagine how much time I spent trying to figure out what PEMDAS was >_> Pretty much took me from page 1 'till here... EDIT: In DK we call it basic math
You should have just Googled it :D
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On April 08 2011 07:59 Zeke50100 wrote:Show nested quote +On April 08 2011 07:58 munchmunch wrote:On April 08 2011 07:53 MandoRelease wrote:On April 08 2011 07:10 mikeymoo wrote:
It really depends on the context. You would never see a formula typed out linearly like this in any paper.
It's like reading "cos2x" and arguing that technically it should be equal to cos(2)*x when most people would see cos(2x). I made an assumption about the equation because it's being asked in the first place. Most arithmetically sound people wouldn't ask this question on a forum, so I assumed that the author was bad at math. Someone bad at math would definitely phrase this question as something he/she had seen on his/her homework, that is, they would write 48/(2(9+3)) as seen on homework as what was typed in the poll.
Yes, it's technically 288. Usually if it is meant to evaluate to 288, it would be written (48/2)(9+3), for clarity. I'm not embarrassed at all to have answered 2. I strongly disagree with the bolded part. Math does not depend on the context. The poll asked for the answer of the calcul (computation ? I don't know what word to use sorry), and the calcul was crystal clear since omitting the mutltiplicative sign here is perfectly correct. However omitting the parentheses in "cos2x" is not, and has never been written as such in any accurate paper/article/book i've read. I don't believe your comparison is correct. The omission of parentheses is made all the time, actually. That's due to laziness, rather than because people believing it's correct. The problem is that people who DO now how to write it "pass on" the incorrect way to do it, creating quite a bit of confusion when it comes to mathematical form >.>
Not due to laziness at all, actually. Granted, it would be incorrect to omit the parentheses in many contexts, but in any context where it can be expected to be unambiguous to the reader, it would be recommended to any mathematical writer to drop the parentheses for aesthetic reasons.
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oh well guess i can troll my algebra and calculous teacher next time
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On April 08 2011 08:00 Ecrilon wrote:
2x has a different order than 2*x. 2x is treated as a single unit in all scientific disciplines. The answer is 2. If the equation were 48/2*(9+3) the answer would be 288.
>_< this is my line of thinking too.... 
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On April 08 2011 08:01 munchmunch wrote:Show nested quote +On April 08 2011 07:59 Zeke50100 wrote:On April 08 2011 07:58 munchmunch wrote:On April 08 2011 07:53 MandoRelease wrote:On April 08 2011 07:10 mikeymoo wrote:
It really depends on the context. You would never see a formula typed out linearly like this in any paper.
It's like reading "cos2x" and arguing that technically it should be equal to cos(2)*x when most people would see cos(2x). I made an assumption about the equation because it's being asked in the first place. Most arithmetically sound people wouldn't ask this question on a forum, so I assumed that the author was bad at math. Someone bad at math would definitely phrase this question as something he/she had seen on his/her homework, that is, they would write 48/(2(9+3)) as seen on homework as what was typed in the poll.
Yes, it's technically 288. Usually if it is meant to evaluate to 288, it would be written (48/2)(9+3), for clarity. I'm not embarrassed at all to have answered 2. I strongly disagree with the bolded part. Math does not depend on the context. The poll asked for the answer of the calcul (computation ? I don't know what word to use sorry), and the calcul was crystal clear since omitting the mutltiplicative sign here is perfectly correct. However omitting the parentheses in "cos2x" is not, and has never been written as such in any accurate paper/article/book i've read. I don't believe your comparison is correct. The omission of parentheses is made all the time, actually. That's due to laziness, rather than because people believing it's correct. The problem is that people who DO now how to write it "pass on" the incorrect way to do it, creating quite a bit of confusion when it comes to mathematical form >.> Not due to laziness at all, actually. Granted, it would be incorrect to omit the parentheses in many contexts, but in any context where it can be expected to be unambiguous to the reader, it would be recommended to any mathematical writer to drop the parentheses for aesthetic reasons.
Being accustomed to the omission of parentheses doesn't make it right 
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On April 08 2011 07:58 munchmunch wrote:Show nested quote +On April 08 2011 07:53 MandoRelease wrote:On April 08 2011 07:10 mikeymoo wrote:
It really depends on the context. You would never see a formula typed out linearly like this in any paper.
It's like reading "cos2x" and arguing that technically it should be equal to cos(2)*x when most people would see cos(2x). I made an assumption about the equation because it's being asked in the first place. Most arithmetically sound people wouldn't ask this question on a forum, so I assumed that the author was bad at math. Someone bad at math would definitely phrase this question as something he/she had seen on his/her homework, that is, they would write 48/(2(9+3)) as seen on homework as what was typed in the poll.
Yes, it's technically 288. Usually if it is meant to evaluate to 288, it would be written (48/2)(9+3), for clarity. I'm not embarrassed at all to have answered 2. I strongly disagree with the bolded part. Math does not depend on the context. The poll asked for the answer of the calcul (computation ? I don't know what word to use sorry), and the calcul was crystal clear since omitting the mutltiplicative sign here is perfectly correct. However omitting the parentheses in "cos2x" is not, and has never been written as such in any accurate paper/article/book i've read. I don't believe your comparison is correct. The omission of parentheses in the context of trigonometric functions is made all the time, actually. There are more things in heaven and earth than exist in your philosophy, I guess.
That does not make it any more correct. Its just lazyness.
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Oh shit. Division isn't commutative. Good game guys. There is no correct answer in this case. Stop following BEDMAS. It was made up by grade school teachers to help you understand the order of operations. It doesn't work in extreme cases because there is no correct way to interpret the equation.
Essentially, 2/3*4 is not the same as (2)(1/3)(4) which it isn't the same as (2/3)(4) which isn't the same as (2)/(3*4). You can't simply convert division into fractional form because the math symbols aren't clear enough. In written form, you interpret the question based on what the symbols show. On one text line, that's impossible to convey without parenthesis.
The best example would be 2/3/4. If you did it (2/3)/4, I haven't specified which / is larger. The computer reads it to the best of its ability. It is limited by computer notation. There is no difference between / and a larger / for a computer, which is why it simply reads it front to end after the regular operations.
The bigger question is then:
Do we treat this as a written, typed or oral question?
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On April 08 2011 08:01 munchmunch wrote:Show nested quote +On April 08 2011 07:59 Zeke50100 wrote:On April 08 2011 07:58 munchmunch wrote:On April 08 2011 07:53 MandoRelease wrote:On April 08 2011 07:10 mikeymoo wrote:
It really depends on the context. You would never see a formula typed out linearly like this in any paper.
It's like reading "cos2x" and arguing that technically it should be equal to cos(2)*x when most people would see cos(2x). I made an assumption about the equation because it's being asked in the first place. Most arithmetically sound people wouldn't ask this question on a forum, so I assumed that the author was bad at math. Someone bad at math would definitely phrase this question as something he/she had seen on his/her homework, that is, they would write 48/(2(9+3)) as seen on homework as what was typed in the poll.
Yes, it's technically 288. Usually if it is meant to evaluate to 288, it would be written (48/2)(9+3), for clarity. I'm not embarrassed at all to have answered 2. I strongly disagree with the bolded part. Math does not depend on the context. The poll asked for the answer of the calcul (computation ? I don't know what word to use sorry), and the calcul was crystal clear since omitting the mutltiplicative sign here is perfectly correct. However omitting the parentheses in "cos2x" is not, and has never been written as such in any accurate paper/article/book i've read. I don't believe your comparison is correct. The omission of parentheses is made all the time, actually. That's due to laziness, rather than because people believing it's correct. The problem is that people who DO now how to write it "pass on" the incorrect way to do it, creating quite a bit of confusion when it comes to mathematical form >.> Not due to laziness at all, actually. Granted, it would be incorrect to omit the parentheses in many contexts, but in any context where it can be expected to be unambiguous to the reader, it would be recommended to any mathematical writer to drop the parentheses for aesthetic reasons.
I agree. Sometimes it just makes more sense to not have any parenthesis. When writing papers I actually spend a ridiculous amount of time rearranging terms in equations so that it is aesthetically pleasing and unambiguous.
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EPT
