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Re: How to introduce a Functional with the results with Solve command?

• To: mathgroup at smc.vnet.net
• Subject: [mg89280] Re: How to introduce a Functional with the results with Solve command?
• From: dh <dh at metrohm.ch>
• Date: Tue, 3 Jun 2008 06:45:20 -0400 (EDT)
• References: <g22tpq$il1$1@smc.vnet.net>

Hi,

it is not too clear to me what you want to do, I will try to guess.

You have a function sol4[rom_] of a parameter rom. Note that rom is a 

dummy parameter, therefore it can not depend on x1. But you may e.g. write:

sol4[Sqrt[x1]]

Only of this we can take the derivative relative to x1. E.g.:

D[sol4[Sqrt[x1]],x1]

Note also, there is a more formal way using Dt. This will give the total 

derivative with symbolic drom/dx1, but this is perhaps not what you want.

hope this helps, Daniel



Kaibin Fu wrote:

> I get the expression of urm which is a function of rom. 

>  

> sol3=Solve[sol2 == 0, urm]; 

> sol4[rom_] = sol3[[1]][[1]][[2]];

> Because rom is a function of x1, I want to take the derivative of the following functional with respect of x1. 

> sol5[x1_]=3*rom -sol4[rom]

> How should I do it?

> If convenient, please send an email to

> kaibinfu at gmail.com

> thanks.

> 





-- 



Daniel Huber

Metrohm Ltd.

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CH-9100 Herisau

Tel. +41 71 353 8585, Fax +41 71 353 8907

E-Mail:<mailto:dh at metrohm.com>

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