Re: how do I solve for this
- To: mathgroup at smc.vnet.net
- Subject: [mg117640] Re: how do I solve for this
- From: Alexei Boulbitch <alexei.boulbitch at iee.lu>
- Date: Tue, 29 Mar 2011 06:51:52 -0500 (EST)
Say, you do: p = \[CapitalNu]*kb*T/(V[T] - \[CapitalNu]*b) - a*\[CapitalNu]^2/V[T]^2 -((a \[CapitalNu]^2)/V[T]^2) + ( kb T \[CapitalNu])/(-b \[CapitalNu] + V[T]) der = D[p, T] (kb \[CapitalNu])/(-b \[CapitalNu] + V[T]) + ( 2 a \[CapitalNu]^2 Derivative[V][T])/V[T]^3 - ( kb T \[CapitalNu] Derivative[V][T])/(-b \[CapitalNu] + V[T])^2 sol = Solve[der == 0, V'[T]][[1, 1]] Derivative[V][T] -> -(( kb \[CapitalNu] (b \[CapitalNu] - V[T]) V[ T]^3)/(-2 a b^2 \[CapitalNu]^4 + 4 a b \[CapitalNu]^3 V[T] - 2 a \[CapitalNu]^2 V[T]^2 + kb T \[CapitalNu] V[T]^3)) Is it what you had in mind? You remember, of coarse, that you cannot use N as a variable in Mathematica. Say I have p=N*kb*T/(V-N*b)-a*N^2/V^2 I want to evaluate the derivative of V with respect to T, keeping p,N,kb,b,a constant. I understand that this can be done by hand. I just want to know whether this can be done by using mathematica. I couldnt understand how to use Solve to do this. maybe there is something else I am not aware of -- Alexei Boulbitch, Dr. habil. Senior Scientist Material Development IEE S.A. ZAE Weiergewan 11, rue Edmond Reuter L-5326 CONTERN Luxembourg Tel: +352 2454 2566 Fax: +352 2454 3566 Mobile: +49 (0) 151 52 40 66 44 e-mail: alexei.boulbitch at iee.lu www.iee.lu -- This e-mail may contain trade secrets or privileged, undisclosed or otherwise confidential information. If you are not the intended recipient and have received this e-mail in error, you are hereby notified that any review, copying or distribution of it is strictly prohibited. Please inform us immediately and destroy the original transmittal from your system. Thank you for your co-operation.