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#51 2011-07-02 22:40:48
- anonimnystefy
- Real Member
Online
Re: Integration by Substitution
got that one.dunno what to do next.
The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“A secret's worth depends on the people from whom it must be kept.” ― Carlos Ruiz Zafón
#52 2011-07-02 22:52:35
- bobbym
- Administrator
Online
Re: Integration by Substitution
Hi;
gAr has a substitution that you will look at too.
In mathematics, you don't understand things. You just get used to them.
Probability is the most important concept in modern science, especially as nobody has the slightest notion what it means.
90% of mathematicians do not understand 90% of currently published mathematics.
#53 2011-07-02 23:04:43
- anonimnystefy
- Real Member
Online
Re: Integration by Substitution
hi
what substitution?
The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“A secret's worth depends on the people from whom it must be kept.” ― Carlos Ruiz Zafón
#54 2011-07-02 23:06:56
- bobbym
- Administrator
Online
Re: Integration by Substitution
My way has led to a integration by parts which is tediuos but amounts to plugging in to a formula.
If gAr has something else it may save you a whole lot of work. So let us wait for him.
In mathematics, you don't understand things. You just get used to them.
Probability is the most important concept in modern science, especially as nobody has the slightest notion what it means.
90% of mathematicians do not understand 90% of currently published mathematics.
#55 2011-07-02 23:10:10
- anonimnystefy
- Real Member
Online
Re: Integration by Substitution
ok,sure.just a question,is it possible to send private messages on this forum?
The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“A secret's worth depends on the people from whom it must be kept.” ― Carlos Ruiz Zafón
#56 2011-07-02 23:11:26
- bobbym
- Administrator
Online
Re: Integration by Substitution
Yes, you must be a real member. That is awarded by MIF. Only he can do it.
In mathematics, you don't understand things. You just get used to them.
Probability is the most important concept in modern science, especially as nobody has the slightest notion what it means.
90% of mathematicians do not understand 90% of currently published mathematics.
#57 2011-07-02 23:12:53
- anonimnystefy
- Real Member
Online
Re: Integration by Substitution
yeah,how often does he come to the forum,because i don't see him active very much?
The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“A secret's worth depends on the people from whom it must be kept.” ― Carlos Ruiz Zafón
#58 2011-07-02 23:15:37
- bobbym
- Administrator
Online
Re: Integration by Substitution
I see him every day.
In mathematics, you don't understand things. You just get used to them.
Probability is the most important concept in modern science, especially as nobody has the slightest notion what it means.
90% of mathematicians do not understand 90% of currently published mathematics.
#59 2011-07-02 23:17:24
- anonimnystefy
- Real Member
Online
Re: Integration by Substitution
when?
The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“A secret's worth depends on the people from whom it must be kept.” ― Carlos Ruiz Zafón
#60 2011-07-02 23:19:01
- anonimnystefy
- Real Member
Online
Re: Integration by Substitution
me and MIF must be opposite time zones.
The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“A secret's worth depends on the people from whom it must be kept.” ― Carlos Ruiz Zafón
#61 2011-07-02 23:20:03
- bobbym
- Administrator
Online
Re: Integration by Substitution
I think so. Also he is usually busy working on the site.
In mathematics, you don't understand things. You just get used to them.
Probability is the most important concept in modern science, especially as nobody has the slightest notion what it means.
90% of mathematicians do not understand 90% of currently published mathematics.
#62 2011-07-02 23:21:36
- anonimnystefy
- Real Member
Online
Re: Integration by Substitution
let's stop this or otherwise there's a possibility that this topic turns into a chat topic.
The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“A secret's worth depends on the people from whom it must be kept.” ― Carlos Ruiz Zafón
#63 2011-07-02 23:24:37
- bobbym
- Administrator
Online
Re: Integration by Substitution
Brought to the front by moderator.
Hi
anonimnystefy wrote:
can anyone help me get:
In mathematics, you don't understand things. You just get used to them.
Probability is the most important concept in modern science, especially as nobody has the slightest notion what it means.
90% of mathematicians do not understand 90% of currently published mathematics.
#64 2011-07-02 23:48:41
- gAr
- Star Member
Offline
Re: Integration by Substitution
Hi,
First lets derive a general formula for
First method is a more common one, integration by parts.
We'll need to use IBP twice, where we end up with the original integral on the RHS, and rearrange it.
Another method struck me:
Constant is not so cool to look at, I agree!
"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?
"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."
#65 2011-07-02 23:55:53
- anonimnystefy
- Real Member
Online
Re: Integration by Substitution
hi gAr
thanks.never thought of that.
The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“A secret's worth depends on the people from whom it must be kept.” ― Carlos Ruiz Zafón
#66 2011-07-03 00:12:57
- gAr
- Star Member
Offline
Re: Integration by Substitution
Hi anonimnystefy,
You're welcome!
The constant is not "not cool" as I thought.
I forgot about substituting x back in the answer!
So what remains is:
Last edited by gAr (2011-07-03 00:13:25)
"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?
"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."
#67 2011-07-18 02:57:17
- gAr
- Star Member
Offline
Re: Integration by Substitution
Hi,
A huge list of integrals, for fun and practice!
http://mpec.sc.mahidol.ac.th/radok/phys … /sec41.htm
http://mpec.sc.mahidol.ac.th/radok/phys … /sec42.htm
http://mpec.sc.mahidol.ac.th/radok/phys … /sec51.htm
Skimming over it, I can say the problems have a quality!
That site is wonderful!
Don't miss the library: http://mpec.sc.mahidol.ac.th/library/oldbooks
Last edited by gAr (2011-07-18 03:21:07)
"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?
"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."
#68 2011-08-02 20:55:16
- gAr
- Star Member
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Re: Integration by Substitution
Hi,
From AMM 
11275
Find
"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?
"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."
#69 2011-08-09 07:48:49
- anonimnystefy
- Real Member
Online
Re: Integration by Substitution
here's one:
The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“A secret's worth depends on the people from whom it must be kept.” ― Carlos Ruiz Zafón
#70 2011-08-09 16:33:00
- gAr
- Star Member
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Re: Integration by Substitution
Hi anonimnystefy,
"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?
"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."
#71 2011-08-09 21:36:07
- anonimnystefy
- Real Member
Online
Re: Integration by Substitution
hi gAr
thanks for looking for the problem.
The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“A secret's worth depends on the people from whom it must be kept.” ― Carlos Ruiz Zafón
#72 2011-08-09 22:13:23
- gAr
- Star Member
Offline
Re: Integration by Substitution
Hi anonimnystefy,
I'm not finished with it yet!
I posted it in haste because I had to go out for a while.
Now I'll take a longer look.
"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?
"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."
#73 2011-08-09 22:23:15
- anonimnystefy
- Real Member
Online
Re: Integration by Substitution
hi gAr
it's ok,take your time.
The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“A secret's worth depends on the people from whom it must be kept.” ― Carlos Ruiz Zafón
#74 2011-08-10 04:59:09
- gAr
- Star Member
Offline
Re: Integration by Substitution
Hi anonimnystefy,
"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?
"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."
#75 2011-08-10 07:10:00
- anonimnystefy
- Real Member
Online
Re: Integration by Substitution
ok i will be waiting.
i don't have the solution.
The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“A secret's worth depends on the people from whom it must be kept.” ― Carlos Ruiz Zafón