∀ ε>0
|1+ 1/n^2 - 1|
= |1/n^2| < ε
n > √(1/ε)
Choose N =[√(1/ε)] + 1
∀n >N
|1+ 1/n^2 - 1| lim(n->∞ ) ( 1+ 1/n^2) =1