Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫  π  -¹ ² ³ °

You are not logged in.

## #1 2013-02-15 20:34:50

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,771
Website

### MY FRIEND and i

My friend is claiming that he has found a proof to show that the "square root of -1" tends to 1.
He will probably show me the proof on Tuesday(if I get enough time to meet him).

Thoughts?

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

Offline

## #2 2013-02-15 20:36:46

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: MY FRIEND and i

That is definitely not true, and there will surely be an error in his "proof".

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

Offline

## #3 2013-02-15 20:42:02

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,771
Website

### Re: MY FRIEND and i

I know this is funny that is why I am excited

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

Offline

## #4 2013-02-15 20:48:43

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: MY FRIEND and i

I am just sad because that guy is going to whip up a proof in which the flaw is very, very well hidden, and that in the short time that you are unable to find it, he will feel superior.

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

Offline

## #5 2013-02-15 20:53:45

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,771
Website

### Re: MY FRIEND and i

Ya the time would be very short.
And I do not know enough about limits to tell whether he is correct.

BTW, Do we have another term for 0/0 other than 'undefined'?

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

Offline

## #6 2013-02-15 20:58:19

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: MY FRIEND and i

The common name for 0/0 is indeterminate. It means a different thing than undefined (which would be something like 1/0).

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

Offline

## #7 2013-02-15 21:00:11

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,771
Website

### Re: MY FRIEND and i

How does it make any difference?
Both just indicate 'nonsense'

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

Offline

## #8 2013-02-15 21:01:16

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: MY FRIEND and i

Yes, but, the first one could actually have a value.

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

Offline

## #9 2013-02-15 21:03:37

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,771
Website

### Re: MY FRIEND and i

How?

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

Offline

## #10 2013-02-15 21:10:25

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,771
Website

### Re: MY FRIEND and i

By the way, How do I fight absurd things like this:

∴ i^2 = -1
Again,

Last edited by bobbym (2013-02-15 22:10:29)

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

Offline

## #11 2013-02-15 21:41:27

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: MY FRIEND and i

√a*√b=√ab only if a,b≥0.

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

Offline

## #12 2013-02-15 22:11:17

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,771
Website

### Re: MY FRIEND and i

Proof?

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

Offline

## #13 2013-02-15 22:25:55

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: MY FRIEND and i

Hi;

If a and b < 0 then it is easy to find a counterexample

Last edited by bobbym (2013-02-15 22:41:54)

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

## #14 2013-02-15 22:36:35

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,771
Website

### Re: MY FRIEND and i

Counter example? Hmmm...

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

Offline

## #15 2013-02-15 22:40:03

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: MY FRIEND and i

Hi Agnishom;

You only need one counterexample to prove any assertion is not always true.

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

## #16 2013-02-15 22:43:19

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: MY FRIEND and i

bobbym wrote:

Hi;

If a and b < 0 then it is easy to find a counterexample

If somebody claims √-1*√-1=√(-1)*(-1) then he can also claim √-2*√-3=√6.

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

Offline

## #17 2013-02-15 22:44:59

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: MY FRIEND and i

Hi;

I was partially answering post #12, not the incorrect proof.

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

## #18 2013-02-15 22:49:18

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,771
Website

### Re: MY FRIEND and i

Okay! What is the square root of i?

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

Offline

## #19 2013-02-15 22:54:31

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: MY FRIEND and i

$\LARGE \inline \bg_green \frac{\sqrt{2}}{2}+\frac{\sqrt{2}}{2}i$

Last edited by bobbym (2013-02-15 22:55:22)

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

## #20 2013-02-15 23:06:50

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: MY FRIEND and i

What's with the green?

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

Offline

## #21 2013-02-15 23:07:19

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: MY FRIEND and i

Cool hah!

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

## #22 2013-02-15 23:25:44

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,771
Website

### Re: MY FRIEND and i

Cool? Perhaps not

How did my latex in #10 get corrected?

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

Offline

## #23 2013-02-15 23:26:23

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: MY FRIEND and i

I corrected it, I hope it is what you wanted to say.

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

## #24 2013-02-15 23:33:06

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,771
Website

### Re: MY FRIEND and i

Nice thanks but i believe latex allowed us to put normal text inside it.

When are you all going to fix up the image upload? I've got something to show

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

Offline

## #25 2013-02-15 23:34:34

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: MY FRIEND and i

MIF is working on that I have things too.

For your latex use \text{} to put ordinary text in latex.

Know this guy?

Last edited by bobbym (2013-02-16 00:38:43)

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline