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#26 2010-09-28 08:12:43
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Integration by Substitution
Hi 123ronnie321;
Welcome to the forum! That is not the correct answer.
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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#27 2010-12-10 07:09:58
- Raven66
- Member
- Registered: 2010-12-10
- Posts: 1
Re: Integration by Substitution
Some similar solved examples on integration by substitution are available at http://www.math24.net/change-of-variable.html.
Last edited by Raven66 (2010-12-10 07:10:39)
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#28 2010-12-10 13:40:46
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Integration by Substitution
Hi Raven66;
Welcome to the forum! That is a nice site. Some nice stuff on surface integrals there.
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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#29 2011-04-20 22:04:39
- 123ronnie321
- Member
- Registered: 2010-09-28
- Posts: 128
Re: Integration by Substitution
Second try-
Hi;
Here is an interesting integral done by substitution.
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#30 2011-04-20 22:30:31
- gAr
- Member
- Registered: 2011-01-09
- Posts: 3,482
Re: Integration by Substitution
Hi 123ronnie321,
Yes, how did you solve it?
"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."
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#31 2011-04-20 22:30:53
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Integration by Substitution
Hi 123ronnie321
Sorry, gAr, we were posting at the same time.
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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#32 2011-04-20 22:45:38
- gAr
- Member
- Registered: 2011-01-09
- Posts: 3,482
Re: Integration by Substitution
Hi bobbym,
Strange! Sage too couldn't do it.
Looks like the packages do not use the properties of definite integrals.
"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."
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#33 2011-04-20 22:56:07
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Integration by Substitution
You know when I posed this was a long time ago. That is exactly what I did too. No one got it for a long time. Very good work!
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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#34 2011-04-20 23:11:18
- gAr
- Member
- Registered: 2011-01-09
- Posts: 3,482
Re: Integration by Substitution
Yes, really a long time ago!
Thanks.
A similar kind of problem:
"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."
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#35 2011-04-20 23:18:02
- 123ronnie321
- Member
- Registered: 2010-09-28
- Posts: 128
Re: Integration by Substitution
Hi bobbym,
Thank you. Nice problem.
Hi gar, Yes that is how i did it too!
Last edited by 123ronnie321 (2011-04-20 23:34:41)
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#36 2011-04-20 23:26:14
- gAr
- Member
- Registered: 2011-01-09
- Posts: 3,482
Re: Integration by Substitution
Hi 123ronnie321,
Okay, good one!
"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."
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#37 2011-06-30 23:23:07
- anonimnystefy
- Real Member
- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,049
Re: Integration by Substitution
hi everyone
could anyone tell me if this i correct,I'm trying to practice calculating integrals:
Last edited by anonimnystefy (2011-07-01 01:02:09)
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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#38 2011-06-30 23:27:49
- anonimnystefy
- Real Member
- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,049
Re: Integration by Substitution
hi
here's the fifth problem cuz it couldn't fit into my last one:
Last edited by anonimnystefy (2011-06-30 23:40:13)
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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#39 2011-06-30 23:40:03
- anonimnystefy
- Real Member
- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,049
Re: Integration by Substitution
hi
seventh problem:
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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#40 2011-06-30 23:44:37
- anonimnystefy
- Real Member
- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,049
Re: Integration by Substitution
hi
can anyone tell me how to get:
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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#41 2011-06-30 23:50:44
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Integration by Substitution
Hi;
How do you integrate sin(u)?
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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#42 2011-07-01 01:02:38
- anonimnystefy
- Real Member
- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,049
Re: Integration by Substitution
hi bobbym
thanks for noticing.i corrected it.
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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#43 2011-07-01 01:06:25
- gAr
- Member
- Registered: 2011-01-09
- Posts: 3,482
Re: Integration by Substitution
Hi anonimnystefy,
All are right then.
CAS shows:
Wolframalpha suggests completing the square.
For some problems, you can use partial fractions.
"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."
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#44 2011-07-01 23:15:47
- anonimnystefy
- Real Member
- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,049
Re: Integration by Substitution
hi all
can anyone help me get:
Last edited by anonimnystefy (2012-06-22 07:29:59)
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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#45 2011-07-02 00:14:01
- anonimnystefy
- Real Member
- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,049
Re: Integration by Substitution
anyone?
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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#46 2011-07-02 00:15:20
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Integration by Substitution
Hi;
Have you done IBP?
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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#47 2011-07-02 00:21:31
- anonimnystefy
- Real Member
- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,049
Re: Integration by Substitution
no.
but i'm not sure how.
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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#48 2011-07-02 00:32:20
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Integration by Substitution
Hi;
That looks like it will end up as an integration by parts.
First clean up the interior of the cosine.
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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#49 2011-07-02 00:35:48
- gAr
- Member
- Registered: 2011-01-09
- Posts: 3,482
Re: Integration by Substitution
Hi,
No need to use that!
It's only a constant angle there.
Using substitution would make it simpler.
"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."
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#50 2011-07-02 00:39:54
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Integration by Substitution
Hi;
the formula will give you
Which cleans up the constant too.
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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