| Title: | Mathematics at DEC | 
| Moderator: | RUSURE::EDP | 
| Created: | Mon Feb 03 1986 | 
| Last Modified: | Fri Jun 06 1997 | 
| Last Successful Update: | Fri Jun 06 1997 | 
| Number of topics: | 2083 | 
| Total number of notes: | 14613 | 
Is there a polynomial whose square has fewer terms? Are there two polynomials with m and n terms, respectively, whose product has fewer than min(m,n) terms?
| T.R | Title | User | Personal Name | Date | Lines | 
|---|---|---|---|---|---|
| 79.1 | AURORA::HALLYB | Mon Jun 11 1984 20:44 | 2 | ||
| Presumably Stan is referring to polynomials over the reals. An easy counterexample (otherwise) would be 2x+y, over the integers modulo 4. | |||||
| 79.2 | HARE::STAN | Tue Jun 12 1984 01:24 | 1 | ||
| I intended that the coefficients be (non-zero) complex numbers. | |||||
| 79.3 | HARE::GILBERT | Tue Jun 12 1984 17:00 | 10 | ||
| Here are two polynomials with 4 terms each, and a product with 2 terms:
	     3     2       2    3            2         2
	p = x  - 2x y + 2xy  - y  = (x - y)(x  - xy + y )
	     3     2       2    3            2         2
	q = x  + 2x y + 2xy  + y  = (x + y)(x  + xy + y )
	     6    6
       pq = x  - y 
 | |||||
| 79.4 | ORPHAN::BRETT | Tue Jun 12 1984 18:50 | 4 | ||
| Okay, now for only one variable.... /Bevin | |||||
| 79.5 | TURTLE::STAN | Tue Jun 12 1984 21:37 | 1 | ||
| Let y=1. | |||||