Let a function be continuous on an open set . Then is said to have the -property if, for each , there exists an such that , where is a closed disk, and for every ,
If has the mean-value property, then is harmonic.
Let a function be continuous on an open set . Then is said to have the -property if, for each , there exists an such that , where is a closed disk, and for every ,
If has the mean-value property, then is harmonic.
Weisstein, Eric W. "Mean-Value Property." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Mean-ValueProperty.html