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**caspertts****Member**- Registered: 2014-05-09
- Posts: 3

first of all, hello I'm new here and I'm not good in math so I decided to join this forum,hope we can help each other!

this is the question that I don't know the answer

D={x|x is an integer such that x^2=2)

list the elements of D

if I √2, I will not get the value of x in integer isn't?

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**zetafunc.****Guest**

caspertts wrote:

if I √2, I will not get the value of x in integer isn't?

So what can you say about the set, D?

**caspertts****Member**- Registered: 2014-05-09
- Posts: 3

zetafunc. wrote:

caspertts wrote:if I √2, I will not get the value of x in integer isn't?

So what can you say about the set, D?

containt no element?

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The set is

Welcome to the forum;

What is your favorite color?

'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'

'But our love is like the wind. I can't see it but I can feel it.' -A Walk to remember

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**caspertts****Member**- Registered: 2014-05-09
- Posts: 3

Agnishom wrote:

The set is

Welcome to the forum;

What is your favorite color?

thanks!my next question,if

A={1}

D={∅}

then A∩D?

sorry for asking simple question like this , favorite color?blue!

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,071

hi caspertts

Welcome to the forum.

A intersection 'phi' is everything in both. But they haven't got any common elements so it's the empty set again.

Have a look here:

http://www.mathsisfun.com/sets/sets-introduction.html

If that's too simple then use the search with the word 'sets' to find lots more.

Bob

Strictly speaking the empty set is { } not {phi}. There is a difference which I'll explain if you want.

*Last edited by bob bundy (2014-05-10 00:30:59)*

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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sorry for asking simple question like this

Do not be sorry. All questions are worthy questions.

Yoda wrote:

A fool, no questioner is. By asking, wiser he becomes.

'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'

'But our love is like the wind. I can't see it but I can feel it.' -A Walk to remember

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,071

All questions are worthy questions.

I agree with your sentiment but what about:

Is it FALSE to say this question is worthy?

Bob

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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Axiom: All questions are worthy.

Question: Is it FALSE to say this question is worthy?

Answer: No. [by axiom]

Which part of the axiom is contradicted?

'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'

'But our love is like the wind. I can't see it but I can feel it.' -A Walk to remember

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,071

I concede your point.

Bob

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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yay!

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'But our love is like the wind. I can't see it but I can feel it.' -A Walk to remember

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,071

Don't get too happy. I may yet find a sentence that does what I was intending.

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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Not necessarily.

There are undoubtedly properties about questions which you cannot prove false.Example: All questions end with a question mark

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'But our love is like the wind. I can't see it but I can feel it.' -A Walk to remember

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**ShivamS****Member**- Registered: 2011-02-07
- Posts: 3,646

bob bundy wrote:

Don't get too happy. I

mayyet find a sentence that does what I was intending.Bob

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,071

hi Agnishom,

After much further thought, I find I am able to find any inconsistency or logical flaw in your theory. I therefore hold it to be a good theory.

Do you want to name it? How about "Agnishom's First Worthiness Theory"?

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**ShivamS****Member**- Registered: 2011-02-07
- Posts: 3,646

bob bundy wrote:

I find I am able to find any inconsistency or logical flaw in your theory.

Your post does not make sense

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,071

O yes. Meant to be 'unable to find'. Whoops.

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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Can we name it 'Fundamental Theorem of Worth'?

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'But our love is like the wind. I can't see it but I can feel it.' -A Walk to remember

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,071

**Fundamental Theorem of Worth** it is then. Congratulations.

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**ShivamS****Member**- Registered: 2011-02-07
- Posts: 3,646

Prove the theorem. I thought it was an axiom.

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,071

ShivamS wrote:

Prove the theorem. I thought it was an axiom.

You are right. Let's amend it to: "**Fundamental Theory of Worth**."

Is that OK ?

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**ShivamS****Member**- Registered: 2011-02-07
- Posts: 3,646

It has not been proven. It must be an axiom or a hypothesis.

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,071

We have an axiom:

Agnishom wrote:

Axiom: All questions are worthy.

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**ShivamS****Member**- Registered: 2011-02-07
- Posts: 3,646

A theory is usually supported by some empirical evidence.

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 15,937

Not really. Number theory, for example.

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.

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