9/3(4-1) another one of those stupid maths thing Watch

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Pheylan
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SmileyGurl13
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#42
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sorry
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LawBore
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Am I being stupid in just working it out with what I learned in Year 7- that is, BODMAS- to come out with 9?
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Simplicity
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(Original post by LawBore)
Am I being stupid in
Pretty much. The answer is 1.

(Original post by nuodai)
And there's no avoiding context in maths; if you study maths to a higher level than, say, GCSE, you'll come across things like functions, where people may write
I have never personally seen f^2(x)=/=ff(x). I would surprised to see
f(X)^2=ff(X).

Also, what when has f^2(x) ever mean't the to differentiate it twice? As that would be stupid and make no sense.

P.S. Also, the orignal problem is clearly 1. I don't see how others can see it as not 1. If I held a gun to your head and said what is correct you would choose 1.

I supose some notation is ambigous like a/b/c. However, I don't see it in this case when if you clearly understand what multiplication is, there is only 1 way to read it. Multiplication and division happen at the same time, so it only makes sense if it's 1.
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z0tx
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(Original post by animated_cadaver)
The question is ambiguous, hence there is no correct answer.

No mathematician in his right mind would ever phrase an equation like that. :rolleyes:
Completely false. There is a correct answer, it's 9.
Here's why: 9/3(4-1)=(4-1)9/3. Now try to get 1 out of the left side.
It would be 1 if we were looking at 9/(3(4-1)). Brackets are not decoration!

Its not ambiguous at all.
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munn
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(Original post by Simplicity)
Pretty much. The answer is 1.


I have never personally seen f^2(x)=/=ff(x). I would surprised to see
f(X)^2=ff(X).

Also, what when has f^2(x) ever mean't the to differentiate it twice? As that would be stupid and make no sense.

P.S. Also, the orignal problem is clearly 1. I don't see how others can see it as not 1. If I held a gun to your head and said what is correct you would choose 1.

I supose some notation is ambigous like a/b/c. However, I don't see it in this case when if you clearly understand what multiplication is, there is only 1 way to read it. Multiplication and division happen at the same time, so it only makes sense if it's 1.
Quite often actually, though typically the notation will have the number of times differentiated in brackets.

Taylor series are almost always written in the form:

f(x+h)=f(x)+h f^{(1)}(x)+\frac{h^2}{2!}f^{(2)}  (x)+\frac{h^3}{3!}f^{(3)}(x)+ \ldots +\frac{h^n}{n!}f^{(n)}(x)


I don't think I've actually seen them written any other way
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Simplicity
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(Original post by z0tx)
Completely false. There is a correct answer, it's 9.
Here's why: 9/3(4-1)=(4-1)9/3. Now try to get 1 out of the left side.
It would be 1 if we were looking at 9/(3(4-1)). Brackets are not decoration!

Its not ******* ambiguous at all.
The answer is wrong. How much Maths do you know? As your reasoning is really bad and so I'm guessing you got a C at GCSEs?
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Simplicity
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(Original post by munn)
Quite often actually, though typically the notation will have the number of times differentiated in brackets.

Taylor series are almost always written in the form:

f(x+h)=f(x)+h f^{(1)}(x)+\frac{h^2}{2!}f^{(2)}  (x)+\frac{h^3}{3!}f^{(3)}(x)+ \ldots +\frac{h^n}{n!}f^{(n)}(x)


I don't think I've actually seen them written any other way

There is a difference between f^(2)(x) and f^2(x). Get some glasses next time you post. Also, I'm familiar with Newtons notations.
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z0tx
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(Original post by Simplicity)
The answer is wrong. How much Maths do you know? As your reasoning is really bad and so I'm guessing you got a C at GCSEs?
Are you joking? Seeing you havn't even explained what you find wrong in my reasoning proves you're the one who hasn't got a clue of what's going on here. By the way, A levels: A*AA. Good night.
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munn
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(Original post by Simplicity)
There is a difference between f^(2)(x) and f^2(x). Get some glasses next time you post. Also, I'm familiar with Newtons notations.
Christ you're a friendly guy aren't you?

If you had glasses yourself you'd have seen that my post said "typically".
The brackets aren't always there.
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Pheylan
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(Original post by Simplicity)
There is a difference between f^(2)(x) and f^2(x). Get some glasses next time you post
No need to be a **** about it
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Simplicity
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(Original post by z0tx)
Are you joking? Seeing you havn't even explained what you find wrong in my reasoning proves you're the one who hasn't got a clue of what's going on here. By the way, A levels: A*AA. Good night.
Nice, what A levels. Media studies?

(Original post by munn)
Christ you're a friendly guy aren't you?

If you had glasses yourself you'd have seen that my post said "typically".
The brackets aren't always there.
Nice red herring again.

The point is that you are stupid if you think that f^2(x) means differentiate twice. No one uses that notation, no one uses Newtons notation in general as it's ****. Even you put brackets around the 2. I don't see what the hell you on about.

Again, get glasses.
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Blazara
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When in doubt, just write the division as if it was a fraction.
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Rahul.S
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saw this on fb....answer is 1
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munn
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(Original post by Simplicity)
Nice, what A levels. Media studies?


Nice red herring again.

The point is that you are stupid if you think that f^2(x) means differentiate twice. No one uses that notation. Even you put brackets around the 2. I don't see what the hell you on about.

Again, get glasses.
It's not stupidity. It's defined by the notation used by the author.
About 2 years ago I was learning something (I cannot for the life of me remember what) which led me to a book written in the 1960s which had something which looked like a taylor series except that the final terms were:

f(n-1)+f(n)+f(n+1)

I racked my brains for hours before finally taking the book to the lecturer who told me that it in fact meant:

f^{(n-1)}+f^{(n)}+f^{(n+1)}

This is a 50 year old book which several teachers still told us was an excellent resource yet used a notation which seems ridiculous by our standards.

The moral of the story is:

Different authors mean different things by notation.

Hell one of my courses used \phi in the coursework then hit us with \varphi in the exam because it was written by a different lecturer. Now most people know that both are simply phi, but yet again it's a case of two different people using different notations for different things.
In my dissertation on the golden ratio I found it notated as \varphi, \Phi, \phi and \tau in the books I researched with no common consensus on what the accepted notation is.
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DFranklin
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It seems it's impossible for any of these threads to not devolve into insults, so I'm closing this.
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