The square root of minus 1

loslobos


Joined: 02/04/2009
Posts: 167

Message Posted:
30/04/2010 22:56

Don't stay up all night on this one. It doesn't exist as a real or imaginary number. I don't care how big your

cray astronomic parallel computer is. Now.... the meaning of life, now, this one's a real bitch !!

No1Doyen


Joined: 04/07/2008
Posts: 16617

Message Posted:
01/05/2010 00:48

In arithmetic, minus multiplied by minus gives plus. (Taking a debt away from someone is really like crediting a positive sum of money - and in a similar way, a sentence containing two negatives becomes positive). Thus, because (- 1) squared equals +1, the answer to Ö (-1) cannot be "minus one" (nor can the result be plus one).

Therefore by definition; if it takes two men a week to walk a fortnight, how many apples in a bunch of grapes?

Navek



Joined: 01/06/2008
Posts: 2656

Message Posted:
01/05/2010 00:55

It might be easier do dig half a hole with a left handed shovel )))

Navek

cyprusishome


Joined: 31/03/2007
Posts: 2381

Message Posted:
01/05/2010 07:00

loslobos,



Sorry, the answer to the question about life, the universe and everything has been answered - it is 42.

donegal



Joined: 23/04/2008
Posts: 48

Message Posted:
01/05/2010 11:08

answer is minus 1 see the argand diagram of complex numbers

johnerebus



Joined: 15/05/2009
Posts: 72

Message Posted:
01/05/2010 12:23

The answer to your life is whatever you want it to be. And please remember: A full stop comes at the end of our sentences... of life!

I wish you well. John

No1Doyen


Joined: 04/07/2008
Posts: 16617

Message Posted:
01/05/2010 13:02

If anybody steals my identity, at least I'll know who to look for.    

No1Doyen


Joined: 04/07/2008
Posts: 16617

Message Posted:
01/05/2010 13:04

Me and my mate have just been fighting over which is the best vowel.

I won.    

No1Doyen


Joined: 04/07/2008
Posts: 16617

Message Posted:
01/05/2010 13:06

I've just been to the hospital where the doctor told me my DNA was backwards.



And?    

No1Doyen


Joined: 04/07/2008
Posts: 16617

Message Posted:
01/05/2010 13:08

I've spent my entire life researching the multiples of zero and it has amounted to nothing.    

loslobos


Joined: 02/04/2009
Posts: 167

Message Posted:
01/05/2010 13:52

Now what multipled by itself gives the result -1

JohnW


Joined: 23/04/2009
Posts: 601

Message Posted:
02/05/2010 09:53

http://www.1728.com/compnum2.htm

elko2



Joined: 24/07/2007
Posts: 4400

Message Posted:
02/05/2010 12:37

Let me put it in simple terms. You can say that there is an angle of 180 degrees between a positive number and a negative number. Hence when you multiply a + no. with a - no., you turn it round by 180 degrees. Simple enough.

Now in real life the imaginary number is very important and it is very handy in electricity. In alternating current in most countries, the voltage goes positive and negative 50 times in a second. One full cycle is made up of 360 degrees naturally. In some cases like inductors the current lags the voltage by 90 degrees. So if this happens twice it will lag by 180 degrees. hence "i" is used for "imaginary" before a number to indicate that if multiplied by a number it will turn it by 90 degrees. If you multiply i4 by i5, the result is -20 because the result will be turned round by 90 degrees twice. Hence the square of "i1" is -1. So the square root of -1 is i1.

This is the best I can do without the use of diagrams.

ismet

(the most helpful member )

elko2



Joined: 24/07/2007
Posts: 4400

Message Posted:
02/05/2010 12:46

The link in msg 12 does not really explain the true nature of an imaginary number. I think my explanation gives a beter insight to the problem. Was I able to make it understandable? What do you think?

ismet

layby_lil



Joined: 13/11/2009
Posts: 141

Message Posted:
02/05/2010 15:26

I think... I've got a headache...... i'll just stick to rock and roll.. that I do understand