RE: a problem with differentiation

*To*: mathgroup at smc.vnet.net*Subject*: [mg29717] RE: [mg29676] a problem with differentiation*From*: Soh Pek Hooi <fbasohph at nus.edu.sg>*Date*: Wed, 4 Jul 2001 03:08:44 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Hi Carlos, thanks. I tried your recommended method and it worked fine. But when I tried to put it in the following format, it said 2t^2 is a not a valid variable. h[t_] := 2t^2 v[h_] := 4/2(h^3 + 4h^2) Function[{h,v}, D[v[h], h]][2t^2, 4/2(h^3+4h^2)] We have a program which requires the Function to be specified so that any expressions for h and v can be passed in. How can we still "hold" on to "h" without h being substituted in the Function? Pek -----Original Message----- From: Carlos Collier To: mathgroup at smc.vnet.net Subject: [mg29717] Re: [mg29676] a problem with differentiation On Tue, 3 Jul 2001, Soh Pek Hooi wrote: Hello you could try the following: h[t_] := 2t^2 v[h_] := 4/2(h^3 + 4h^2) D[v[h], h] 2*(8*h + 3*h^2) saludos carlos > Hi, > > If I have > h= 2t^2 > v = 4/2(h^3+4h^2) > > How do I evaluate D[v,h] in terms of h without having h to be substituted in > the following manner? > > Function[{h,v}, D[v, h]][2t^2, 4/2(h^3+4h^2)] > > Will appreciate your comments. > > Pek > >