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#1 2007-09-21 12:04:30

Prad
Guest

Integration problem

Integration problem:

Dear all,

Does anybody have any idea how i can integrate the following:

where A and c are constants.

Thanks for your help.

Best,
Prad

#2 2007-09-21 13:30:29

bossk171
Member
Registered: 2007-07-16
Posts: 305

Re: Integration problem

I don't think it can be done. I plugged it into The Integrator and it didn't give an answer.


There are 10 types of people in the world, those who understand binary, those who don't, and those who can use induction.

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#3 2007-09-21 14:59:09

prad
Guest

Re: Integration problem

hmm.. I thought this might be the case, but i wasn't sure.

Thanks for your help.

#4 2007-09-21 16:53:05

Identity
Member
Registered: 2007-04-18
Posts: 934

Re: Integration problem

I plugged it into my calculator and got

Last edited by Identity (2007-09-21 16:53:41)

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#5 2007-09-22 00:44:28

HallsofIvy
Guest

Re: Integration problem

Identity wrote:

I plugged it into my calculator and got

Unfortunately, that has nothing to do with the question.  The derivative was with respect to t, not y. 

  You could separate the variables as


  Can you integrate the left side of that?

#6 2007-09-22 00:48:09

Hallsofivy
Guest

Re: Integration problem

Is there no way to edit posts on this board?  That was supposed to be 


  I forgot one "}"!

#7 2007-09-22 01:51:47

John E. Franklin
Member
Registered: 2005-08-29
Posts: 3,588

Re: Integration problem


igloo myrtilles fourmis

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#8 2007-09-22 02:59:27

bossk171
Member
Registered: 2007-07-16
Posts: 305

Re: Integration problem

Is this an integral for school, or for fun? Did you just make it up? Would an estimation work (like Riemann sums)?

Last edited by bossk171 (2007-09-22 06:42:12)


There are 10 types of people in the world, those who understand binary, those who don't, and those who can use induction.

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#9 2007-09-22 04:46:20

Prad
Guest

Re: Integration problem

Oh, this problem is a differential equation representing the change in species over time used in photochemical kinetics.  The equation has been derived from a law known as Beer-lambert's law.

I've been working on this equation for a while, and I have modified it from various research papers to fit my kinetic scheme. 

Though.. it is difficult to integrate.   Is there any way it may be possible to numerically integrate the equation?

This is not for school, and appoximation would be fine. 

Thanks,
Prad

#10 2007-09-22 04:49:57

Prad
Guest

Re: Integration problem

Hallsofivy wrote:

Is there no way to edit posts on this board?  That was supposed to be 


  I forgot one "}"!

Hmm... I'm not sure...
I'll have a try...thanks!

Prad

#11 2007-09-22 05:21:57

bossk171
Member
Registered: 2007-07-16
Posts: 305

Re: Integration problem

Yes, read this wiki on Riemann sums it'll give you an idea of how to go about doing it by hand.

Or you can plug it into a TI-83 or another Graphing program and evaluate it numerically that way.

Last edited by bossk171 (2007-09-22 05:22:17)


There are 10 types of people in the world, those who understand binary, those who don't, and those who can use induction.

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