Re: Extracting terms of a polynomial into a list and then multiply each
- To: mathgroup at smc.vnet.net
- Subject: [mg90397] Re: Extracting terms of a polynomial into a list and then multiply each
- From: Bill Rowe <readnews at sbcglobal.net>
- Date: Tue, 8 Jul 2008 02:27:11 -0400 (EDT)
On 7/7/08 at 5:05 AM, deepyogurt at gmail.com (Bob F) wrote:
>Can anyone suggest a way to extract the terms of a polynomial into a
>list. For example the integral of the series expansion of
>1 -------------------- (1 - t^2) ^(1/2)
>could be expressed in Mathematica (the first 50 terms) as
>Integrate[Normal[Series[(1 - t^2)^(-1/2), {t, 0, 50}]], {t, 0,
>x}]
>and gives the polynomial
>x + x^3/6 + (3 x^5)/40 + (5 x^7)/112 + (35 x^9)/1152 + (63 x^11)/
>2816 + (231 x^13)/13312 + (143 x^15)/10240 +
>(6435 x^17)/557056 + (12155 x^19)/1245184 + (46189 x^21)/
>5505024 + . . .
Any expression can be converted to a list using Apply. For example,
In[17]:= List @@ (3 x^2 + 2 x + 1)
Out[17]= {1,2 x,3 x^2}
Another function you might find useful is CoefficientList. For example,
In[19]:= CoefficientList[3 x^2 + 2 x + 1, x]
Out[19]= {1,2,3}