[Date Index] [Thread Index] [Author Index]

Re: complex analysis problem in mathematica 3.0

• To: mathgroup at smc.vnet.net
• Subject: [mg48475] Re: [mg48459] complex analysis problem in mathematica 3.0
• From: Hugh Walker <hwalker at gvtc.com>
• Date: Tue, 1 Jun 2004 03:02:50 -0400 (EDT)
• Sender: owner-wri-mathgroup at wolfram.com

On Sunday, May 30, 2004, at 11:13 PM, BranasMan wrote:

> i have a complex function:
>
> H(s)=1 / (s^3 + 2s^2 + 2s + 1)
>
> whan i replace "s" with j*w (j=sqrt(-1)) i get:
>
> H=1 / (1 + j2w -2w^2 - jw^3)
>
> i would like to get that function in shape of :
> H=something + j*something_else i.e. the complex
> and real part apart.
>
> i played with Re and Im,but it seems that the fact that
> "w" is a variable confuses mathematica?!
>
> i would reeeealy appreciate any help,and maybe perhaps some
> links for me to learn to use mathematica better.

Here is one way:

h = (1 / (s^3 + 2s^2 + 2s + 1) /. s -> I w) // ComplexExpand

==========
Hugh Walker
Gnarly Oaks