Re: Applying Math 6
- To: mathgroup at smc.vnet.net
- Subject: [mg82355] Re: Applying Math 6
- From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
- Date: Thu, 18 Oct 2007 04:55:08 -0400 (EDT)
- Organization: The Open University, Milton Keynes, UK
- References: <ff4etv$dcu$1@smc.vnet.net>
Johan Mars wrote:
> I need to fit x-y data to the equation below and also need to determine
> the derivative.
> Please help.
>
> y=exp[-(a*ln(x))/bc]^d + exp[-(a*ln(x)/be]^f
>
> This equation is used in adsorption studies and is normally referred to
> as the Dubinin-Izotova equation.
To help you started with Mathematica syntax, the first expression
defines a function and the second expression takes the first derivative.
In[1]:= y[x_] := Exp[-(a*Log[x])/bc]^d + Exp[-(a*Log[x])/be]^f
In[2]:= y'[x]
Out[2]=
-1 - a/bc -(a/bc) -1 + d -1 - a/be -(a/be) -1 + f
a d x (x ) a f x (x )
-(-------------------------------) - -------------------------------
bc be
Regards,
--
Jean-Marc