Re: functional notation
- To: mathgroup at smc.vnet.net
- Subject: [mg26053] Re: [mg26034] functional notation
- From: BobHanlon at aol.com
- Date: Sat, 18 Nov 2000 23:08:07 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
In a message dated 11/17/00 4:54:12 AM, BlimbaumJE at ncsc.navy.mil writes:
>When I type in the following 2 lines:
>
>
> D[f[x],x]*D[x[t],t];
>
> %/.{x->Function[t,at]
>
> I get back
>
> a * f ' [Function[t, at ] ] but what I want to get back is a*f '
>[t] or a*f ' [x]
>
> I'm trying to do something with just functional notation and I want
>certain derivatives to 'stay as is' once they are computed..I've looked
>at
>Hold,etc. and dont know how to use them or even if they are the correct
>way
>to go.
>
SetAttributes[a, Constant];
Dt[f[x], x]*Dt[x, t];
% /. x -> a*t
a*Derivative[1][f][a*t]
Bob Hanlon