Re: [Phys-L] Halfway point ???

[brian whatcott <betwys1@sbcglobal.net>]

On 4/4/2015 9:47 AM,  a Phys-L contributor commented in this way:
> in an expression such as
>
>     0 - a - b - c - d
>
> you keep on subtracting, and in an expression such as
>
>     1 / a / b / c / d
>
> you keep on dividing.  Therefore the reciprocal of
> a / b is 1 / b * a or 1 / (a / b) ... not simply
> 1 / a / b.
In an effort to coerce angels to dance on pinheads, I notice that the 
term 1/b*a results in a value which varies with one's choice for the 
precedence of arithmetic operators.
This precedence is taught in mnemonic form which varies from country to 
country -  e.g. Canada, USA, UK; where the mnemonic is
 rendered as BODMAS, PEMDAS etc., or failing these, LTR (left to right) 
not to mention Polish and Reverse Polish notation.
It will not have escaped you that some people may execute D before M 
while others insist on executing M before D.
Neither mnemonic is definitively right or wrong however.
See a story given here for example...

<http://www.wyzant.com/resources/blogs/236411/the_order_of_operations_pemdas_bodmas_that_you_learned_in_elementary_school_is_wrong>

 ...or in TinyURL form
http://tinyurl.com/pjt9dg7

Parentheses are omitted at your risk!

Which just goes to show.... there is nothing so prone to error as a 
correction.    (And this is itself a correction, of course!)

Brian Whatcott