[Date Index]
[Thread Index]
[Author Index]
Re: How to define the coefficients of a polynomial to be real?
 To: mathgroup at smc.vnet.net
 Subject: [mg100955] Re: [mg100925] How to define the coefficients of a polynomial to be real?
 From: "David Park" <djmpark at comcast.net>
 Date: Thu, 18 Jun 2009 20:46:33 0400 (EDT)
 References: <18883255.1245315881604.JavaMail.root@n11>
The command you want is ComplexExpand, which is often overlooked by new
users. ComplexExpand assumes all symbols are real, except those you specify
to be complex.
poly[z_] = a0 + a1 z + a2 z^2 + a3 z^3;
poly[1 + I]
ComplexExpand[Re[%]]
a0 + (1 + I) a1 + 2 I a2  (2  2 I) a3
a0 + a1  2 a3
David Park
djmpark at comcast.net
http://home.comcast.net/~djmpark/
From: BHUPALA [mailto:bhupala at gmail.com]
I have a 10th order polynomial (a0+a1 z+a2 z^2 + ... + an z^10). I
want to define all the coefficients to be real. I want to substitute z
= 1+i and extract only real part of it.
I have done this by defining
Element[a0,Reals];
Element[a1,Reals];
Prev by Date:
Re: How can I parse arguments of an expression unevaluated?
Next by Date:
Re: PDF import problem
Previous by thread:
Re: How to define the coefficients of a polynomial to be real?
Next by thread:
Re: How to define the coefficients of a polynomial to be real?
