Minus one times minus one equals one?

[jabee]

F*&^%ing accountants........

 

watch jabee doesn't send you a bill for £90 per hour for all this maths

 

£90 per hour...since when did people expect me to work on the cheap

[jabee]

Why oh why do people have to introduce an effing x into any conversation about maths?

 

Right then, we'll try x and y then;

 

Assuming 0 * x = 0 and logically y+(-y)=0, and also assuming that x and y are both positive (greater than 0).

 

then

 

[y+(-y)] * x = 0 * x;

 

xy+(-y)(x) = 0 * x

 

therfore

 

xy+(-y)(x)=0

 

Assuming positive multiplied by positive equals a positive, then the value of xy must be positive. if this is the case and the addition of (-y)(x) gives the value zero, then (-y)(x) must be the inverse of xy, in other words, negative!

 

Invoice in the post!

Edited November 30, 2006 by jabee

[jabee]

I think I've just found a beneficial side effect to this -1 x -1 = +1 business.

 

Tomorrow I go out and buy that new air rifle I fancy for exactly £1000, It will then appear on my next statement as a debit of -£1000. January, I then phone the camera shop and buy that new lense for exactly £1000. In theory as these monthly £1000 debits multiply I should be £1,000,000 up by the time my March statement arrives and have some shiny new kit!

 

Ahhh, but they don't multiply, they accumulate, therfore your into Barcs for 2 grand

[RobStubbs]

Most of this only works on paper surely?

Can you demonstrate what a -1 looks like? You can't take what is not there. Therefor -1 =0

 

Den

 

I think most bank managers can tell you what a minus number is, or credit card companies.

 

Rob.

[Trubshaw]

Right then, we'll try x and y then;

 

Assuming 0 * x = 0 and logically y+(-y)=0, and also assuming that x and y are both positive (greater than 0).

 

then

 

[y+(-y)] * x = 0 * x;

 

xy+(-y)(x) = 0 * x

 

therfore

 

xy+(-y)(x)=0

 

Assuming positive multiplied by positive equals a positive, then the value of xy must be positive. if this is the case and the addition of (-y)(x) gives the value zero, then (-y)(x) must be the inverse of xy, in other words, negative!

 

Invoice in the post!

 

Je ne comprend pas!!!!!!!

 

Qu'est ce que un invoice?

 

Merde.

[jabee]

At the end of the day, mathamatics is based on theorems, however, most of these have practical applications.....calculus got men on moon etc.

 

The concept of negative values is essential for the operation of all our economic, financial and accounting systems for a start!

 

My wife challenged me as to why minus times minus should be plus. I tried to illustrate the point (walking along the tiles in the kitchen lino. Minus = backwards, ie turning round 180 degrees. If you do it twice you're facing forwards again).

 

But am I right that the real answer is that we define this to be the case, because then we have an arithmetic system which conveniently describes a number of things in the natural world?

 

Bet you wish you had never started this one

[Norrie]

At the end of the day, mathamatics is based on theorems, however, most of these have practical applications.....calculus got men on moon etc.

 

 

 

Eh !!!!, Sums got men on the moon !!!!!!!! Geezus, whatever next !!! Bet they had something to do with Square Pies as well !!!

[Snatcher]

Norrie same school mate

 

Chicken,mince,cheese pies are cosher but them "thagarus" pies do your heed in !

 

Are you up for a bit of "lads week 2007" at the Mull? Have chucked Stan the man a bit cheese as well

[jabee]

A quote from Einstien;

 

"As far as the laws of mathematics refer to reality, they are not certain, and as far as they are certain, they do not refer to reality"

 

 

And a maths joke;

 

Did you hear the one about the statistician?

 

.....Probably

 

And finally, bringing us back to the subject in hand;

 

A mathematician and a biologist are sitting in a street cafe watching people going in and coming out of the house on the other side of the street.

 

First they see two people going into the house. Time passes. After a while they notice three people coming out of the house.

The biologist says "they have reproduced" but the mathematician replies "no, when exactly one person enters the house then it will be empty again."

 

I'll get my coat again

Edited November 30, 2006 by jabee

[Happy Dude]

A quote from Einstien;

 

"As far as the laws of mathematics refer to reality, they are not certain, and as far as they are certain, they do not refer to reality"

And a maths joke;

 

Did you hear the one about the statistician?

 

.....Probably

 

And finally, bringing us back to the subject in hand;

 

A mathematician and a biologist are sitting in a street cafe watching people going in and coming out of the house on the other side of the street.

 

First they see two people going into the house. Time passes. After a while they notice three people coming out of the house.

The biologist says "they have reproduced" but the mathematician replies "no, when exactly one person enters the house then it will be empty again."

 

I'll get my coat again

 

how many coats do you have john??

 

mind you, if you won't work for £90PH they are probably all fur ones

 

did you hear about the constipated mathematician??

 

had to work it out with a pencil and a sliderule