Re: how do I solve for this
- To: mathgroup at smc.vnet.net
- Subject: [mg117677] Re: how do I solve for this
- From: Gary Wardall <gwardall at gmail.com>
- Date: Tue, 29 Mar 2011 06:58:48 -0500 (EST)
- References: <imfa6a$io5$1@smc.vnet.net>
On Mar 24, 6:33 am, thinktank1985 <di... at umich.edu> wrote: > 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 t= his 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 For an explicit form try: -D[N*kb*T/(V - N*b) - a*N^2/V^2 - p, T]/ D[N*kb*T/(V - N*b) - a*N^2/V^2 - p, V] For an implicit form try: "First branch" D[Solve[p == N*kb*T/(V - N*b) - a*N^2/V^2, V][[1]][[1]][[2]], T] "Second branch" D[Solve[p == N*kb*T/(V - N*b) - a*N^2/V^2, V][[2]][[1]][[2]], T] "Third branch" D[Solve[p == N*kb*T/(V - N*b) - a*N^2/V^2, V][[3]][[1]][[2]], T] If my calculus is ok. Gary