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On April 08 2011 08:04 munchmunch wrote:Show nested quote +On April 08 2011 08:02 Zeke50100 wrote:On April 08 2011 08:01 munchmunch wrote: [ 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 No, but aesthetics can be a good reason.
So, incorrect notation should be advocated because it looks better?
I'll concede that if you're in a group of people that will ALWAYS understand what IS right, yet communicate to each other in a technically incorrect manner for ease of communication, that's fine. However, that's clearly not what's happening, otherwise people wouldn't be confused.
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order of operations yo, follow the rules of the game to win.
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48/2(9+3)=48/2(12)=48/2*12=24*12=288
1/2x=1/2*x=(1/2)*x=.5x
Yes, I did engineering at a university level.
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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 correct. Just because your average Java compiler doesn't distinguish between the two doesn't mean there is no difference.
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A Simple Math Problem? Obviously not. In most languages where it is unambiguous they get mad at you for not using ascii, lol "÷" Python even complains that 2() is an invalid function.
My students often get tripped up when typing "6.28/2pi" doesn't give them something close to 1. Even odder is that my 20 year old TI-81 does give .9995, while a newer TI-84 gives 9.865.
So don't rely on a possibly buggy implementation of order of operations and just use an extra * /
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On April 08 2011 08:02 Aruno wrote:Show nested quote +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....
So you're telling me that 2x is not 2*x. Please prove this mathematically.
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I am in a pretty crappy university, my last math course that i took was a grade 11 uni level in high school and i knew the right answer right away for this question. Not sure why people struggling with this.
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Too confusing syntax. There may be a rule regarding this, but it's still confusing and nothing published should be written like this.
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i think people are missing the point. it isnt about PEDMAS and whatnot, its about seeing 2x as one variable or not. in this case, i saw 2(9+3) as 1 variable(?), so these had the first priority over others.
so 48/2(9+3) = 2 while 48/2*(9+3) = 288
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On April 08 2011 08:09 jnkw wrote:Show nested quote +On April 08 2011 08:02 Aruno wrote: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.... So you're telling me that 2x is not 2*x. Please prove this mathematically. There is a difference between something's order and something's value. The proof is left to the reader.
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When multiplying fractions the basic rule comes to something like this; a/b * c/d = ac/bd Some people see this question as 48/2 (a fraction) multiplied by (9+3)/1 (another fraction) which in turn = 48(9+3)/2 = 576/2, which equals 288 Others see it as 48 ÷ 2(9+3) (not a fraction) and use BEDMAS or PEDMAS to solve the question and they get 2 as the answer.
I saw the second scenario before the first because my calculator has both the "/" and the "÷" symbols. (Should I post a picture of my calculator with both answers?)
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On April 08 2011 08:09 gyth wrote:Obviously not. In most languages where it is unambiguous they get mad at you for not using ascii, lol "÷" Python even complains that 2() is an invalid function. My students often get tripped up when typing "6.28/2pi" doesn't give them something close to 1. Even odder is that my 20 year old TI-81 does give .9995, while a newer TI-84 gives 9.865. So don't rely on a possibly buggy implementation of order of operations and just use an extra * /
ye my friend used a TI-81 to check this "problem" and he got 2
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On April 08 2011 08:08 Zeke50100 wrote:Show nested quote +On April 08 2011 08:04 munchmunch wrote:On April 08 2011 08:02 Zeke50100 wrote:On April 08 2011 08:01 munchmunch wrote: [ 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 No, but aesthetics can be a good reason. So, incorrect notation should be advocated because it looks better? I'll concede that if you're in a group of people that will ALWAYS understand what IS right, yet communicate to each other in a technically incorrect manner for ease of communication, that's fine. However, that's clearly not what's happening, otherwise people wouldn't be confused.
Don't forget, you and I are talking about trigonometric functions, not the original problem.
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On April 08 2011 08:09 Ratel wrote: I am in a pretty crappy university, my last math course that i took was a grade 11 uni level in high school and i knew the right answer right away for this question. Not sure why people struggling with this.
Your first and last statements may have a common explanans.
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On April 08 2011 08:08 munchmunch wrote:Show nested quote +On April 08 2011 08:06 Zeke50100 wrote:On April 08 2011 08:03 Blisse wrote: 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? The problem is that there IS a way, and ONLY one way, to interpret it correctly. If you follow PEMDAS, you will get the right answer, every single time. The problem is that people don't realize that fractions with multiple terms cannot exist without parenthesis when a "/" is used. I decided not to tell you to brush up on your reading comprehension in my last reply to avoid being snarky. But now it is unavoidable: put aside your amazing grade school education and read the thread.
What about it? A discussion of how things are communicated to each other, the conventions people are used to, and other topics to which my post holds complete relevance? That's great. You might want some of that amazing grade-school education, by the way. I'll share some with you, if you really want some.
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The reason this is difficult to most people is because the division sign is so rarely used, it is almost always "/", and as munchmunch has pointed out, the question is too vague to correctly decide a correct answer, congrats on the post OP, would have been better to post it on the first though.
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On April 08 2011 08:09 jnkw wrote:Show nested quote +On April 08 2011 08:02 Aruno wrote: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.... So you're telling me that 2x is not 2*x. Please prove this mathematically. This isn't mathematics, it's notation. Remember how Mathematica deals with this? Surely you've ran into this problem while writing your math papers before...
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On April 08 2011 08:09 jnkw wrote:Show nested quote +On April 08 2011 08:02 Aruno wrote: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.... So you're telling me that 2x is not 2*x. Please prove this mathematically.
he's saying 2x implies (2*x), you're saying it implies 2*x without the brackets.
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Lol, this thread is non-sense, it has nothing in common in math. The result can actually be everything because nobody defined meaning of these operations. A would expect some more interesting discussion than this. Mathematics is not calculating, omg.
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i first went into this thread thinking its some kind of joke thread but then i saw all the dicussion now im confused
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