Proof that math is wrong

DoNotDisturb

Senior member
Jul 24, 2002
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that doesn't prove that math is wrong, that proves that for that problem it is an exception.

if u were to add: 1 + 1 using the traditional real number system, would it not equal 2? yes, and thats math.

if 5x = 15, would not x = 3? yes, it would, thus, that proof is not valid for everything.
 

aux

Senior member
Mar 16, 2002
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Short answer: you are using (line 2 -> line 3) something like e^(a*b) = (e^a)^b, which is true for real a and b only (and in your case a = 2*pi*i, which is a complex number).

This has something to do with the funny way the logarithm function (as an inverse of the power function) is defined in a complex domain, but the argument would be too technical for ATOT :)


 

RaynorWolfcastle

Diamond Member
Feb 8, 2001
8,968
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Originally posted by: aux
Short answer: you are using (line 2 -> line 3) something like e^(a*b) = (e^a)^b, which is true for real a and b only (and in your case a = 2*pi*i, which is a complex number).

This has something to do with the funny way the logarithm function (as an inverse of the power function) is defined in a complex domain, but the argument would be too technical for ATOT :)

heh, time to break out the ol' Complex vars textbook ;)
 

Triumph

Lifer
Oct 9, 1999
15,031
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Why would e^2*pi*i = 1? e is a number, 2.71828182828182818 or close to it. 2*pi is roughly 6.28. I don't think e^2*pi*i is = 1.
 

TuxDave

Lifer
Oct 8, 2002
10,571
3
71
I think the flaw comes in when it comes from the step that (1)^(x/2pi) = 1. In fact, I shall disprove it by counter example. =)

Proof why (1)^(x/2pi) != 1 all the time

I choose x to be pi.... therefore 1^1/2 = +- 1

-Dave-

<edit> Cuz x is a variable, you can't conclude much about 1^x for any generic case.
 

Grminalac

Golden Member
Aug 25, 2000
1,149
1
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Hmm, wouldn't
cos(x)=([1] x/2pi + [1] -x/2pi);
cos(x)=(x/2pi+ -x/2pi);
cos(x)=(0/2pi);
cos(x)=0