Question

,,救命···讨论数列Xn=【n+(-1)^n-1】/n 的极限容易看出,当n无限增大时,数列Xn=【n+(-1)^n-

Answer 1

(n + (-1)^(n-1))/n

= 1 + ((-1)^(n-1))/n

|(n + (-1)^(n-1))/n - 1| = |(-1)^(n-1)|/n

= 1/n < ε (当n > 1/ε)