Math Is Fun Forum
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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;
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.
Do you mean me or 123ronnie321. Please use the usernames.
Sorry, opinions have little weight in mathematics. Just saying someone is wrong is adversarial and unproductive.
You must back up your claims. Can you prove your statement?
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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