Re: a problem with differentiation

*To*: mathgroup at smc.vnet.net*Subject*: [mg29707] Re: a problem with differentiation*From*: "Orestis Vantzos" <atelesforos at hotmail.com>*Date*: Wed, 4 Jul 2001 03:08:31 -0400 (EDT)*Organization*: National Technical University of Athens, Greece*References*: <9hs0sk$br6$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Define h=2t^2 but v:=4/2(h^3+4h^2) The SetDelayed in the definition of v should not disturb your code. It does allows this though: In[55]:= Block[{h = H}, Function[{H}, D[v, h] // Evaluate]] Out[55]:= Function[{H}, 2(8 H + 3 H^2)] The result is a pure Function, which eliminates the problem of h spontaneously evaluating into 2t^2. Orestis "Soh Pek Hooi" <fbasohph at nus.edu.sg> wrote in message news:9hs0sk$br6$1 at smc.vnet.net... > 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 >