Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °
You are not logged in.
#26 2010-09-29 06:12:43
- bobbym
- Administrator
Offline
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.
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.
#27 2010-12-11 06:09:58
- Raven66
- Novice
Offline
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 (2010-12-11 06:10:39)
#28 2010-12-11 12:40:46
- bobbym
- Administrator
Offline
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.
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.
#29 2011-04-21 20:04:39
- 123ronnie321
- Full Member
Offline
Re: Integration by Substitution
Second try-
bobbym wrote:
Hi;
Here is an interesting integral done by substitution.
#30 2011-04-21 20:30:31
- gAr
- Star Member
Offline
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."
#31 2011-04-21 20:30:53
- bobbym
- Administrator
Offline
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.
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.
#32 2011-04-21 20:45:38
- gAr
- Star Member
Offline
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."
#33 2011-04-21 20:56:07
- bobbym
- Administrator
Offline
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.
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.
#34 2011-04-21 21:11:18
- gAr
- Star Member
Offline
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."
#35 2011-04-21 21:18:02
- 123ronnie321
- Full Member
Offline
Re: Integration by Substitution
Hi bobbym,
Thank you. Nice problem.
Hi gar, Yes that is how i did it too!
Last edited by 123ronnie321 (2011-04-21 21:34:41)
#36 2011-04-21 21:26:14
- gAr
- Star Member
Offline
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."
#37 2011-07-01 21:23:07
- anonimnystefy
- Real Member
Offline
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 23:02:09)
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
#38 2011-07-01 21:27:49
- anonimnystefy
- Real Member
Offline
Re: Integration by Substitution
hi
here's the fifth problem cuz it couldn't fit into my last one:
Last edited by anonimnystefy (2011-07-01 21:40:13)
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
#39 2011-07-01 21:40:03
- anonimnystefy
- Real Member
Offline
Re: Integration by Substitution
hi
seventh 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
#40 2011-07-01 21:44:37
- anonimnystefy
- Real Member
Offline
Re: Integration by Substitution
hi
can anyone tell me how to get:
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
#41 2011-07-01 21:50:44
- bobbym
- Administrator
Offline
Re: Integration by Substitution
Hi;
How do you integrate sin(u)?
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.
#42 2011-07-01 23:02:38
- anonimnystefy
- Real Member
Offline
Re: Integration by Substitution
hi bobbym
thanks for noticing.i corrected it.
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
#43 2011-07-01 23:06:25
- gAr
- Star Member
Offline
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."
#44 2011-07-02 21:15:47
- anonimnystefy
- Real Member
Offline
Re: Integration by Substitution
hi all
can anyone help me get:
Last edited by anonimnystefy (2012-06-23 05:29:59)
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
#45 2011-07-02 22:14:01
- anonimnystefy
- Real Member
Offline
Re: Integration by Substitution
anyone?
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
#46 2011-07-02 22:15:20
- bobbym
- Administrator
Offline
Re: Integration by Substitution
Hi;
Have you done IBP?
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.
#47 2011-07-02 22:21:31
- anonimnystefy
- Real Member
Offline
Re: Integration by Substitution
no.
but i'm not sure how.
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
#48 2011-07-02 22:32:20
- bobbym
- Administrator
Offline
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.
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.
#49 2011-07-02 22:35:48
- gAr
- Star Member
Offline
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."
#50 2011-07-02 22:39:54
- bobbym
- Administrator
Offline
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.
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.