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## #1 2010-11-13 01:41:55

123ronnie321
Member
Registered: 2010-09-28
Posts: 128

### Challenge

All u hv to do is find functions satisfying -

f` = g
g`= h
h`= f

f,g,h are different functions.
where f means f(x) and f` means f`(x)

-------
A simpler version -

f` = g
g`= f

f(0) = 1
g(0) = 0
find f(1)

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## #2 2010-11-13 11:04:00

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

### Re: Challenge

Hi 123ronnie321;

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 2010-11-15 03:17:57

123ronnie321
Member
Registered: 2010-09-28
Posts: 128

### Re: Challenge

i did it this way

Last edited by 123ronnie321 (2010-11-21 04:01:15)

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## #4 2010-11-15 05:56:50

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

### Re: Challenge

That does not give you the analytical answer. Do you know what those series represent?

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 2010-11-16 19:25:56

123ronnie321
Member
Registered: 2010-09-28
Posts: 128

### Re: Challenge

hi bobby

i tried condensing those series and i got the result very similar to what you posted. I must have made some silly error while calculating.
i wrote the series of e^x, e^wx & e^(w^2)x {where w = complex cube root of unity} and added the three......

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## #6 2010-11-17 01:09:24

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

### Re: Challenge

Hi;

What you probably did wrong was you forgot to divide by 3.

Where 1,w1 and w2 are the roots of unity.

Same answer as I got. But that is not how I did it.

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 2010-11-19 17:40:15

sameer mishra
Member
Registered: 2010-08-27
Posts: 64

### Re: Challenge

hello friend in my openion you are wrong in frist question

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## #8 2010-11-19 17:57:35

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

### Re: Challenge

Hi sameer mishra;

sameer mishra wrote:

hello friend in my openion you are wrong in frist question

Comments like that are kind of confusing. Can you be more specific. We both have names which will help to differentiate us from each other.

Sorry, opinions have little weight in mathematics. Just saying someone is wrong is adversarial and unproductive.