Re: Multiplying Polynomials
- To: mathgroup at smc.vnet.net
- Subject: [mg117893] Re: Multiplying Polynomials
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Sat, 2 Apr 2011 17:05:37 -0500 (EST)
Use Expand vice expand
Bob Hanlon
---- TBone <TBone at yahoo.com> wrote:
=============
This is very simple and I freely confess my ingnorance.
I'm trying to set up a generating function to count some letters of the
alphabet. Specifically, I need to multiply two polynomials in the
variable x, do some surgery on the result, and continue with another
letter.
Here is my problem.
I start with:
expand[(1+ax+a^2x^2+...)*(1+bx+b^2x^2+...)]
and continue with:
expand[(1+ax+bx+abx^2+...)*(1+cx+c^2x^2+...)]
Howerver, it chokes on the following:
expand[(1 + a x + b x + c x + a^2 x^2 + a b x^2 + b^2 x^2 + a c x^2 + b
c x^2 +
c^2 x^2 + a^2 b x^3 + a b^2 x^3 + a^2 c x^3 + a b c x^3 + b^2 c x^3 +
a c^2 x^3 + b c^2 x^3 + a^2 b^2 x^4 + a^2 b c x^4 + a b^2 c x^4 +
a^2 c^2 x^4 + a b c^2 x^4 + b^2 c^2 x^4 + a^2 b^2 c x^5 + a^2 b c^2 x^5 +
a b^2 c^2 x^5 + a^2 b^2 c^2 x^6)*(1 + dx + d^2 x^2)]
What gives?
TIA!!
--TB