Open Balls
Updated: October 21, 2020
Let (X,d) be a metric space. Let a∈X and δ>0. The subset of X consisting of those points x∈X such that d(a,x)<δ is the called the open ball of radius δ and denoted:
B(a;δ)
Open Balls
Let (X,d) be a metric space. Let a∈X and δ>0. The subset of X consisting of those points x∈X such that d(a,x)<δ is the called the open ball of radius δ and denoted:
B(a;δ)