| Singular https://www.singular.uni-kl.de/forum/ |
|
| SOS : Substitution 1/x to a poly!!! https://www.singular.uni-kl.de/forum/viewtopic.php?f=10&t=1857 |
Page 1 of 1 |
| Author: | Guest [ Sat Sep 18, 2010 4:29 pm ] |
| Post subject: | SOS : Substitution 1/x to a poly!!! |
Hello everybody! How can we substitute the variable x of a polynomial with 1/x or 1/(x+1)?? We ask you because when we divide 1/x system returns Zero! For example: If we have a poly p(x)=x and substitute with the command f(x)=subst(p(x),x,1/x) system returns f(x)=0. But we expect to get f(x)=1/x.  Its an emergency!!! 
|
|
| Author: | hannes [ Mon Sep 20, 2010 9:52 am ] |
| Post subject: | Re: SOS : Substitution 1/x to a poly!!! |
The area, you are working in is the set of polynomial: the division in that ring ignores remainder: 1/x is 0 with remainder 1 which is ignored. You seem to want to work in the field of rational functions: in order to do so, define a ring with rational functions a coefficients: Code: ring r=(0,a),x,dp;
poly p=x; subs(p,x,1/a); -> 1/(a) |
|
| Page 1 of 1 | All times are UTC + 1 hour [ DST ] |
| Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/ |
|