Journal of approximation theory vol:87 issue:1 pages:112-115
date:UNIV AMSTERDAM,DEPT MATH & COMP SCI,NL-1018 TV AMSTERDAM,NETHERLANDS
It is shown that if weighted polynomial w(n)P(n) with deg P-n less than or equal to n converge uniformly on the support of the extremal measure associated with w, then they converge to 0 everywhere else. It is also shown that uniform approximation on the support can always be characterized by a closed subset Z having the property that a function can be approximated if and only if it vanishes on Z. (C) 1996 Academic Press, Inc.