# 9/3(4-1) another one of those stupid maths thingWatch

This discussion is closed.
#1
People keep saying it's 1 cos 4-1 = 3 and 3 * 3 = 9 and 9/9 = 1, which is all true but if that were the correct method wouldn't it need to be 9/(3(4-1)).

OKAY i'm sorry I just wanted to make sure I wasn't missing something cos everyone was saying 1.
14
7 years ago
#2
At then end of the day, does this really matter...
0
7 years ago
#3
9..
0
7 years ago
#4
This is why the world must be educated in LaTeX.
2
7 years ago
#5
Contrary to popular belief, it does not make you cleverer than someone to ask them to solve an ambiguous statement and for them to get a different answer to you.
0
7 years ago
#6
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7 years ago
#7
One trillion, bananas that is.
2
7 years ago
#8
(Original post by SmileyGurl13)
People keep saying it's 1 cos 4-1 = 3 and 3 * 3 = 9 and 9/9 = 1, which is all true but if that were the correct method wouldn't it need to be 9/(3(4-1)).
The question is ambiguous, hence there is no correct answer.

No mathematician in his right mind would ever phrase an equation like that.
0
7 years ago
#9
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7 years ago
#10
1
7 years ago
#11
whether it's 9 or 1- what are we all going to achieve at the end of the day
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7 years ago
#12
Multiplication and division happen with equal precedence from left to right before addition and subtraction.

1
7 years ago
#13
TSR needs to install something to detect threads with anything of the form a/b(c+d) in the title, stamp the words AMBIGUOUS NOTATION over any other mention it and then print out a massive hand to slap the OP with.

This thread will soon be locked and deleted, making my post redundant, so I won't put any effort into justifying my claim that the notation is ambiguous, but it is. You're wrong if you claim that it's definitely and unquestionably one answer or the other. There are implicit brackets, meaning that either a/b(c+d) = (a/b)(c+d), or that a/b(c+d) = a/(b(c+d)). That is, or . It's not made clear from the notation which it is, and you can't decide conclusively without making up a non-standard rule (e.g. 'work from left to right'). This is why people who don't know any better go with their first instinct and the battle commences.

The real question is this. Why won't it stop?!
6
7 years ago
#14
(Original post by nuodai)
TSR needs to install something to detect threads with anything of the form a/b(c+d) in the title, stamp the words AMBIGUOUS NOTATION over any other mention it and then print out a massive hand to slap the OP with.

This thread will soon be locked and deleted, making my post redundant, so I won't put any effort into justifying my claim that the notation is ambiguous, but it is. You're wrong if you claim that it's definitely and unquestionably one answer or the other. There are implicit brackets, meaning that either a/b(c+d) = (a/b)(c+d), or that a/b(c+d) = a/(b(c+d)). That is, or . It's not made clear from the notation which it is, and you can't decide conclusively without making up a non-standard rule. This is why people who don't know any better go with their first instinct and the battle commences.

The real question is this. Why won't it stop?!
No, you are wrong, it is not ambiguous, multiplication and division happen left to right. This is a standard rule and is also how computers operate.
6
#15
(Original post by nuodai)
TSR needs to install something to detect threads with anything of the form a/b(c+d) in the title, stamp the words AMBIGUOUS NOTATION over any other mention it and then print out a massive hand to slap the OP with.

This thread will soon be locked and deleted, making my post redundant, so I won't put any effort into justifying my claim that the notation is ambiguous, but it is. You're wrong if you claim that it's definitely and unquestionably one answer or the other. There are implicit brackets, meaning that either a/b(c+d) = (a/b)(c+d), or that a/b(c+d) = a/(b(c+d)). That is, or . It's not made clear from the notation which it is, and you can't decide conclusively without making up a non-standard rule (e.g. 'work from left to right'). This is why people who don't know any better go with their first instinct and the battle commences.

The real question is this. Why won't it stop?!
Okay I'm sorry I admit I was wrong, can you delete this thread now I'm fed up with the negs.
2
7 years ago
#16
(Original post by eliotball)
No, you are wrong, it is not ambiguous, multiplication and division happen left to right. This is a standard rule and is also how computers operate.
What ****e.
0
7 years ago
#17
(Original post by eliotball)
No, you are wrong, it is not ambiguous, multiplication and division happen left to right. This is a standard rule and is also how computers operate.
No, that isn't a standard rule, it's a method used to make Year 8 pupils ask less questions when presented with something like 2×3×6×12 to evaluate, and the rule doesn't exist outside of the world of KS3 maths.

Notation serves to make our lives easier, and any rules which refer only to notation (e.g. 'work left to right') are not mathematical rules, they're guidelines for notation and are open to interpretation depending on what notation you use. In fact, if I wrote 1+x/3+x I'd expect it to be interpreted as instead of .

"9/3(4-1)" is written ambiguously; it can have no evaluation until it is clarified.

And for what it's worth, computers don't uniformly operate like that. There are differences even between different programming languages, where some work from right to left, for example. And computers operate in the way they were programmed -- computers can't deal with ambiguity and so the options are either to present "ERROR" or to interpret it in one way or the other. If a computer interprets an ambiguous statement in one particular way, it doesn't mean that way is right, it just means that it defaults to a particular interpretation of the statement.

(Original post by SmileyGurl13)
Okay I'm sorry I admit I was wrong, can you delete this thread now I'm fed up with the negs.
Well I can't delete it
0
7 years ago
#18
0
#19
(Original post by nuodai)
No, that isn't a standard rule, it's a method used to make Year 8 pupils ask less questions when presented with something like 2×3×6×12 to evaluate, and the rule doesn't exist outside of the world of KS3 maths.

Notation serves to make our lives easier, and any rules which refer only to notation (e.g. 'work left to right') are not mathematical rules, they're guidelines for notation and are open to interpretation depending on what notation you use. In fact, if I wrote 1+x/3+x I'd expect it to be interpreted as instead of .

"9/3(4-1)" is written ambiguously; it can have no evaluation until it is clarified.

Well I can't delete it
*sigh* I was green before all this :P
2
7 years ago
#20
I felt physically sick when I glimpsed the title.
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