differentiate a function of a function

*To*: mathgroup at smc.vnet.net*Subject*: [mg75071] differentiate a function of a function*From*: "kem" <kemelmi at gmail.com>*Date*: Mon, 16 Apr 2007 04:13:41 -0400 (EDT)

Hi, I was wondering how do I define a function in mathematica to be able to differentiate it etc, where some of the parameters of this function should be also a function. For example I want to be able to do the following operations: 1) to say that f is a function: f(x,y) = Tan[t(x,y)+a(x,y)] 2) take D[f,x] , such that also t(x,y) and a(x,y) will be also differentiated 3) be able to substitute these into some equation like: f_x f_xy = 8 Thanks a lot kem

**Follow-Ups**:**Re: differentiate a function of a function***From:*anguzman@ing.uchile.cl

**Re: differentiate a function of a function***From:*leigh pascoe <leigh@cephb.fr>

**Re: differentiate a function of a function***From:*"Chris Chiasson" <chris@chiasson.name>