Problem: let E⊆Rn and let y be a limit point of E. Prove that there exists a sequence xh=y of elements of E such that xh→y when h→+∞.
In the following work, with Br(a) I mean the ball of radius r>0 and center a∈Rn.
My work: by hypothesis y be a limit point of E, hence for each ϵ>0 we have (Bϵ(y)∖{y})∩E=∅. Being the intersection non-empty, there exists xϵ∈(Bϵ(y)∖{y})∩E. By definition of intersection, this means that xϵ=y and xϵ∈E. Let h∈N, choosing ϵ=1/(h+1), from x1/(h+1)∈B1/(h+1)(y) it follows that x1/(h+1)→y when h→+∞ because, from the definition of ball in Rn, we have ∥x1/(h+1)−y∥<h+11→0 when h→+∞.
Is my proof correct?
In the following work, with Br(a) I mean the ball of radius r>0 and center a∈Rn.
My work: by hypothesis y be a limit point of E, hence for each ϵ>0 we have (Bϵ(y)∖{y})∩E=∅. Being the intersection non-empty, there exists xϵ∈(Bϵ(y)∖{y})∩E. By definition of intersection, this means that xϵ=y and xϵ∈E. Let h∈N, choosing ϵ=1/(h+1), from x1/(h+1)∈B1/(h+1)(y) it follows that x1/(h+1)→y when h→+∞ because, from the definition of ball in Rn, we have ∥x1/(h+1)−y∥<h+11→0 when h→+∞.
Is my proof correct?