Limit exercises in Advanced Mathematics 【1】lim(1/n2)*cos nx=0【2】lim0.99…… 99=1 【3】 【4】 Try to prove: if the sequence xn converges, then the sequence is bounded

Limit exercises in Advanced Mathematics 【1】lim(1/n2)*cos nx=0【2】lim0.99…… 99=1 【3】 【4】 Try to prove: if the sequence xn converges, then the sequence is bounded

1.1/n ^ 2 when n tends to infinity, by definition, if ε has | [1 / N ^ 2] - 0 | n, M > N, there is | am an|