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## #1 2012-12-17 23:55:37

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,773
Website

### Can you find x^5 + 1/(x^5) without solving for x?

If x^2 - 3x + 1 = 0
then find x^5 + 1/x^5

'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.

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## #2 2012-12-18 00:11:57

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

### Re: Can you find x^5 + 1/(x^5) without solving for x?

Hi Agnishom;

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.

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## #3 2012-12-18 00:26:32

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,773
Website

### Re: Can you find x^5 + 1/(x^5) without solving for x?

What do I need to know in order to find out the expansion of (x +1/x)^5?

'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.

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## #4 2012-12-18 00:31:35

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

### Re: Can you find x^5 + 1/(x^5) without solving for x?

All problems have a trick associated with them. Good problem solvers have lots of tricks up their sleeves.

All these problems are solved by turning something of the form

Notice how artificially the polynomial given expands into that form.

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.

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## #5 2012-12-18 00:35:21

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,773
Website

### Re: Can you find x^5 + 1/(x^5) without solving for x?

bobbym wrote:

]

How do I get this? Do I need the binomial theorem?

'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.

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## #6 2012-12-18 00:37:13

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

### Re: Can you find x^5 + 1/(x^5) without solving for x?

Exactly or Pascals triangle.

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.

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## #7 2012-12-18 00:41:07

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,773
Website

### Re: Can you find x^5 + 1/(x^5) without solving for x?

Hmm... Thanks!

'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.

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## #8 2012-12-18 00:45:18

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

### Re: Can you find x^5 + 1/(x^5) without solving for x?

Hi Agnishom;

You are welcome. Please have patience you are improving. "All things come to he who waits - pappym.

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.

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## #9 2012-12-18 01:08:35

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,773
Website

### Re: Can you find x^5 + 1/(x^5) without solving for x?

If you don't mind, is "bobbym" your real name?

'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.

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## #10 2012-12-18 01:13:07

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

### Re: Can you find x^5 + 1/(x^5) without solving for x?

Yes, pappym was my dear old Dad. A good ole boy from deep in Alabama.

[removed]

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.

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## #11 2012-12-18 06:55:42

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

### Re: Can you find x^5 + 1/(x^5) without solving for x?

And what was removed?

I really like the "Pass me the chicken" quote from pappym.

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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## #12 2012-12-18 07:07:24

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

### Re: Can you find x^5 + 1/(x^5) without solving for x?

anonimnystefy wrote:

And what was removed?

My real age of course!

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.

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## #13 2012-12-18 08:51:31

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

### Re: Can you find x^5 + 1/(x^5) without solving for x?

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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## #14 2012-12-18 08:58:09

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

### Re: Can you find x^5 + 1/(x^5) without solving for x?

That he did. That was removed also.

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.

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## #15 2012-12-18 16:49:02

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,773
Website

### Re: Can you find x^5 + 1/(x^5) without solving for x?

So, bobbym wants to be more anonymous than anonymnistefy?

'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.

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## #16 2012-12-18 19:11:08

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

### Re: Can you find x^5 + 1/(x^5) without solving for x?

If I wanted to be anonymous I would not have told you the answers.

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