Author Topic: -1 = 1  (Read 968 times)

Mike

  • Jackass In Charge
  • Posts: 11248
  • Karma: +168/-32
  • Ex Asshole - a better and more caring person.
-1 = 1
« on: June 13, 2006, 05:56:42 PM »
Given
i = √-1
√a * √b = √(a*b)

-1 = i2 = (√-1)*(√-1) = √(-1 * -1) = √1 = 1

Proof that -1 = 1 :P

Ken Fitlike

  • Jackass V
  • Posts: 1568
  • Karma: +25/-22
  • Ebeneezer McScrooge
Re: -1 = 1
« Reply #1 on: June 13, 2006, 06:10:16 PM »
-1 = i^2  ????

edit: er - I mean:  √a * √b = √(a*b) is true for some prescribed limit of values for a and b and I suspect the roots of negative numbers aren't included.

But then, what I know about maths can be scribbled down on the back of a postage stamp. ;)
« Last Edit: June 13, 2006, 08:12:56 PM by Ken Fitlike »
And what rough beast, its hour come round at last,
Slouches towards Bethlehem to be born?.

Mike

  • Jackass In Charge
  • Posts: 11248
  • Karma: +168/-32
  • Ex Asshole - a better and more caring person.
Re: -1 = 1
« Reply #2 on: June 13, 2006, 08:22:53 PM »
well if i = √-1 then you square both sides i2 = -1 right?

And you are spot on:  √a * √b = √(a*b) is only valid for a>=0, b >= 0

Ken Fitlike

  • Jackass V
  • Posts: 1568
  • Karma: +25/-22
  • Ebeneezer McScrooge
Re: -1 = 1
« Reply #3 on: June 13, 2006, 09:36:00 PM »
>>well if i = √-1 then you square both sides i2 = -1 right?<<

Yes, I got that, hence my edit - 2 hours later. ;)
And what rough beast, its hour come round at last,
Slouches towards Bethlehem to be born?.