It seems like everyone has a different definition of ":"
When you say, "everyone knows" you are implying I am a nobody. When I was in first or second grade, they taught us the story of "The Emperor's Clothes" which has an enormous impact on me.
I believe ":" means ratio such as in similar triangles a:b:c equals d:e:f. I can back this up with the following websites
| http://www.pen.k12.va.us/Div/Winchester/jhhs/math/facts/symbol.html |
| http://www.roma.unisa.edu.au/07305/symbols.htm#Division |
| Error! Hyperlink reference not valid. |
If you cannot find any websites to justify your definition, then you are not talking a universal language. It sounds narrow minded, but I would like everyone to speak the same language.
Let's say you define the semi colon to mean the horizontal line. In your equation, I wold not know if you wrote this super fraction first and then added the b term later or if the b term is part of the semicolon expression. I think
Princecharming
Rob van Wik
Atadricourses
are using 3 different definitions for the semi colon which are not found on the reputable websites and which I haven't heard of. The only way to change my mind is to produce reputable websites with new definitions for the semi colon.
It is difficult not to believe what we were taught in elementary school. I was taught in elementary school that everyone in Denmark rides bicycles because Denmark is flat. When I got there, it wasn't flat and I didn't see many bicycles.
Regards,
Brian
__._,_.___From: princecharming134Sent: Friday, November 30, 2007 4:45 AMSubject: [Math4u] Re: 26 - 14 : 2 x 3 + 4² = ?
There is a big difference between the division symbol and the colon.
Let's take the quadradic equation as an example:
-b+ (the square root of b^2 -4ac):2a
we all know that even though this formula is one big fraction, all operations above and below the fraction are done before dividing.
What would happen written like this?
-b+ (the square root of b^2 -4ac)/2a
If I read / as a division symbol, I would complete all equations under the square root and then divide it by 2a before I complete the addition/subtractio
n with the lonely b regards
PC
--- In Math4u@yahoogroups.com, "Rob van Wijk" <robvanwijk@. ..> wrote:
>
>
> Here's the recap and all solutions for these non-problems:
>
> Order of operations:
> - Plus and minus are at the same priority level (defining minus to be
> higher priority than plus is a cute hack, but since an expression such
> as "1 - 2 - 3 = ??" will still require the additional "in case of same
> precedence, eval from left to right"-rule, it's pretty pointless).
> - Same for multiply and divide.
> - In case of even the slightest possibility of doubt: just add braces,
> then you are *sure* everyone understands!!
>
> Division symbol:
> - In elementary school we were first tought to use the "colon with a dash"
> symbol. Then "just plain colon" was introduced as a "shorthand" for that.
> Later on, in highschool we switched to using a slash. Sorry, can't link
> to a website (or would you like a link to the website of my elementary
> school? :p ).
> - This mailing list is kinda bound to computers. Yes, there *is* a symbol
> for division. However (sparing you the technical details) there are quite
> severe problems with actually using it (as has been demonstrated). In the
> interest of using a solution that is easy and works universally, in comp.
> sci. we just use a slash for division. May I recommend everyone here also
> follows that convention?
>
> And, to give the long-awaited answer to the original formula:
> (note the use of "^2" instead of "²"; another case of "easy solution that
> just works")
> 26 - 14 : 2 x 3 + 4^2
> == { exponentation }
> 26 - 14 : 2 x 3 + 16
> == { multiply and divide, left to right, first operator encountered }
> 26 - 7 x 3 + 16
> == { multiply and divide, left to right, second operator encountered }
> 26 - 21 + 16
> == { add and substract, left to right, first operator encountered }
> 5 + 16
> == { add and substract, left to right, second operator encountered }
> 21
>
> Google calculator agrees with me:
> http://www.google.nl/search? q=26+-+14+ %2F+2+x+3+ %2B+4%5E2
> 26 - ((14 / 2) x 3) + (4^2) = 21
> (My my, what a nice coincidence, I had to change both the ":" and "²" to
> "/" and "^2" respectively to make it work. Maybe this is the universally
> accepted solution to a non-problem...?)
>
> Grtz,
> Rob
> // If this mail sounds like I'm annoyed with this thread it's because I am
>
>
> -------- Original-Nachricht --------
> > Datum: Sun, 25 Nov 2007 17:01:24 -0000
> > Von: "princecharming134" sossi82@...
> > An: Math4u@yahoogroups.com
> > Betreff: [Math4u] Re: 26 - 14 : 2 x 3 + 4² = ?
>
> > [Brian's comment to Princecharming134: This is useful information on how
> > to make the "÷" sign. However the "/" sign has a very precise meaning
> > and implies nothing. OK, you treated ":" as "( )/( )" but is this right
> > or are you just making up stuff? Can you quote a reputable website?]
> >
> > There is a division symbol available on your PC.
> >
> > It looks like this ÷
> >
> > You can copy and paste it from this post if you wish or you may click
> > on "insert" then "symbols" then look for the division sign on
> > Microsoft word.
> >
> > For those who are not aware as to how to make the division symbol,
> > they have been using /. the problem is that this can imply
> > either a fraction or a division sign.
> >
> > My previous post I treated the : as a fraction.
> >
> > 26 minus 14 over 2 times 3 plus 4 squared.
> >
> > In which case, you must complete all operations above and below the
> > fraction before you can divide.
> > regards,
> > Princecharming134
> >
> >
>
> --
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