RE: The value of a partial derivative

*To*: mathgroup at smc.vnet.net*Subject*: [mg26737] RE: [mg26717] The value of a partial derivative*From*: "David Park" <djmp at earthlink.net>*Date*: Fri, 19 Jan 2001 02:14:13 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Anastasius, Here is one method, using substitution rules: expr = a*x + b*x^2; D[expr, x] % /. {a -> 1, b -> 2, x -> 3} a + 2 b x 13 Here is another method, using a function definition for the original expression. By using separate square brackets for the parameters, (a, b), and the variable, x, you can use the standard Mathematica derivative notation. f[a_, b_][x_] := a*x + b*x^2 f[1, 2]'[3] 13 David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ > From: Anastasius Moumtzoglou [mailto:anas1 at hol.gr] To: mathgroup at smc.vnet.net > Hi, > > I have derived the partial derivative of an expression and I would like > to give values to the parameters in order to get a value for the partial > derivative. Is there a way I could do it using Mathematica 3.0? > > ---------------------------------------------------------------------- > Anastasius Moumtzoglou > 1) Educational & Tecnological Institutions, > Department of Health Services Management > 2) National School of Public Health, > Department of Health Services Management > 3) "P. & A. Kyriakou" Children's Hospital > Personal Page: http://www.geocities.com/moumtzoglou/ > Email:anas1 at hol.gr > >