help me as my brain has gone to mush...
TP - multiplication has a higher precedence than addition and subtraction. That measn you have to do it first. You must multiply 9 by 8 before you carry out the adds/subs.
when all the operators have the same precedence you do work from left to right.
and i'm wrong on MH I think - it's goes to 2/3 doesn't it?
Yeah! that's right. BCDB
It's amazing I think
I was worried that I wouldn't get it right, and I'm a statistician by qualification. Especially since I struggled to get my head round teh switching problem before (it's a Bayesian thing, isn't it?)
Monty Hall is Bayesian.
now help me out with the explanation of arithmetic
Yes Melli I am, but if I knew what BODMAS meant I'd know if I knew it or not.
an example very like yours TP is given in the first few lines
(if you find wikipedia more credible than me)
ah right.. yes.
Mellifera i understand you!
Garr come on!
Garr - wanna hint?
Precedence is just a way of avoiding ambiguity in an operation without brackets.
x+n*y ... how do we know whether the person who wrote that operation means add xn to x then multiply by y; or do they mean multiply y by n then add to x. We know because of precedence. With no brackets we have to do the multiplication first, so it is "multiply n by y then add to x" that is meant.
If, conversely, what the person writing teh operation wants to express is "add n to x then multiply the whole thing by y" then they would have to write:
(x+n)*y ... the addition in the brackets has to be done *before* the multiplication, so we can override precedence with brackets.
Of course in the first example we could express "multiply n by y then add to x" as:
x+(n*y) ... but the brackets are superfluous, because of the precedence of multiplication over addition. We already know we have to multiply first, so we don't need the brackets to tell us.
Next week, partial differential equations and hyperplanes. Remember to bring your sextants and plumb lines. I'm just off to get a new tank top.
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