Re: Log(ln) Function + 2 Parameters + Greater
- To: mathgroup at smc.vnet.net
- Subject: [mg89334] Re: Log(ln) Function + 2 Parameters + Greater
- From: jerry <jerry45632 at yahoo.com>
- Date: Fri, 6 Jun 2008 06:46:18 -0400 (EDT)
- References: <g22tp5$ikl$1@smc.vnet.net> <g237c4$q2n$1@smc.vnet.net> <g25ntv$hug$1@smc.vnet.net> <g27r3a$d64$1@smc.vnet.net>
Thanks to you (and the others) for giving some explanation of this. I've just never seen this form before and would have had no idea it existed. David Park wrote: > If one considers a to be a 'parameter' and x to be the true 'variable' then > the advantage of that form is that it is easy to write derivatives with > respect to the variable. > > f[a_][x_] := x (a + Log[x])^2 > > Just write the dereivative as: > > f[a]'[x] > > (This definition is stored under SubValues[f].) > > But with the other form: > > Clear[f] > f[a_, x_] := x (a + Log[x])^2 > > You have to write the derivative as one of the two following form: > > D[f[a, x], x] > Derivative[0, 1][f][a, x] > >