Re: Derivative help
- To: mathgroup at smc.vnet.net
- Subject: [mg39468] Re: Derivative help
- From: Paul Abbott <paul at physics.uwa.edu.au>
- Date: Mon, 17 Feb 2003 04:34:51 -0500 (EST)
- Organization: The University of Western Australia
- References: <b1dg35$7ar$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
In article <b1dg35$7ar$1 at smc.vnet.net>, "Steve Chiang" <stevezx at attbi.com> wrote: > Hi, all. I'm new to Mathematica. I went to the help section for my > question but it only further confused me. I'm basically trying to take the > first derivative of (ln(x))^x. Here is my syntax: f = (ln(x))^x. In contrast to most responses in this thread this syntax is ok -- as long as you use TraditionalForm for input (under the Cell menu | Default Input FormatType). Personally I prefer TraditionalForm for input and output. > But then when I evaluate f ', it says nothing but ((ln(x))^x)' which is > nothing new. In TraditionalForm you could enter f = (ln(x))^x D[f,x] Alternatively, you can make f an explicit function of x, Clear[f] f[x_] = (ln(x))^x f'[x] or make f a pure function. Clear[f] f = Function[x, (ln(x))^x] f' Cheers, Paul