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Old 10-16-2005, 11:54 AM
ninjia3x ninjia3x is offline
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Join Date: Mar 2005
Posts: 7
Default Re: Ok so I just proved 1 = -1. Someone help me find my error.

[ QUOTE ]
Hi guys. First post in this forum.

Working on a problem set recently, a few friends and I accidentally discovered a proof of -1=1, and for the life of us we can't find out what we did wrong. And it's not like we're math slouches either; we're all graduate students in physical/theoretical chemistry.

From what I understand posting TeX doesn't work on 2+2, so you'll have to follow my algebra.

Start with the identity

(E-V)^(1/2) = (E-V)^(1/2)

Now multiply each side by -1, except on the RHS substitute i^2 for -1 (where i of course is the imaginary number).

(-1)(E-V)^(1/2) = (i^2)(E-V)^(1/2)

Now divide through by i

(-1/i)(E-V)^(1/2) = i*(E-V)^(1/2)

But since i is just the square root of -1, we can subsume it into the square root of E-V

(-1)[(E-V)/-1]^(1/2) = [(-1)(E-V)]^(1/2)

and then rearrange the interior of the square root to find

(-1)(V-E)^(1/2) = (V-E)^(1/2)

or

-1 = 1.

No dividing by zero in this proof either. Where did I make a mistake?

The Doc

[/ QUOTE ]


(-1/i)(E-V)^(1/2) = i*(E-V)^(1/2)

for the (-1/i), times top and bottom by i

you get -i/i^2 = -i/-1 = i

so u have i*(E-V)^(1/2) = i*(E-V)^(1/2)

...pretty obvious mistake u made having root(-1) = -i
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