The Student Room Group

integration question

Integration is not straight forward as derivatives, so it needs experience to solve it. Can anyone make a table of what are the possible situations and how to solve them?

Ie:

1) integral of product of two functions where one is the derivative of the other
2) integral of product of two functions where .....

etc

thanks!
Reply 1
Original post by studos
Integration is not straight forward as derivatives, so it needs experience to solve it. Can anyone make a table of what are the possible situations and how to solve them?

Ie:

1) integral of product of two functions where one is the derivative of the other
2) integral of product of two functions where .....

etc

thanks!


give an example as I am not sure what exactly you want
You may be interested in the Risch algortihm.
Original post by NotLandau
You may be interested in the Risch algortihm.



Probably not.

Original post by TeeEm
give an example as I am not sure what exactly you want


He wants a checklist to go through so he knows what technique to use. IBP, substitution for something else.
Reply 4
Original post by Kvothe the arcane
Probably not.



He wants a checklist to go through so he knows what technique to use. IBP, substitution for something else.


all yours then ...
Original post by TeeEm
all yours then ...


You're the teacher. Don't you have a resource with the common type of A level integration techniques listed? I just stare at the problem and hope for the best. Generally I'm okay.
Reply 6
Original post by Kvothe the arcane
You're the teacher. Don't you have a resource with the common type of A level integration techniques listed? I just stare at the problem and hope for the best. Generally I'm okay.


integration is an art !!
not a flow chart ...
I usually advise students to contemplate the possibility of employing easier direct methods before considering substitution or integration by parts. Just because an integral looks sophisticated doesn't mean you need to sacrifice half of all available brain cells. Hope this is useful. Peace.

http://www.whitegroupmaths.com/2010/11/random-thoughts-on-most-dreaded.html
Original post by TeeEm
integration is an art !!
not a flow chart ...


How do online integrators work? Surely there MUST be an algorithm/flowchart.
Reply 9
Original post by maggiehodgson
How do online integrators work? Surely there MUST be an algorithm/flowchart.


humans are not line integrators ... and that is why humans can integrate expressions which a computer fails
Original post by TeeEm
humans are not line integrators ... and that is why humans can integrate expressions which a computer fails



I suppose that's true but for the ones they can integrate there must be a set of instructions musn't there. It would be interesting to know for us, who don't have the art, but also understanding that we cannot progress any further than painting by numbers.
Reply 11
Original post by maggiehodgson
I suppose that's true but for the ones they can integrate there must be a set of instructions musn't there. It would be interesting to know for us, who don't have the art, but also understanding that we cannot progress any further than painting by numbers.


I sincerely cannot help.
Original post by TeeEm
I sincerely cannot help.


It doesn't matter. I just joined in the conversation because I too have also often wished for a set of rules. I suppose question, question and more question does the trick in due course.

Thanks for your replies. The quest for the "Holy Grail" can stop now. hahaha
Reply 13
Please practice instead of memorising a set of instructions. That way techniques will come intuitively and you won't have to refer to a memorised flowchart. Maybe take a look at a few worked examples to get an idea?

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