求极限 lim sin pi(n^2+1)^(1/2)
问题描述:
求极限 lim sin pi(n^2+1)^(1/2)
答
[(n^2+1)^(1/2) - n] = [(n^2+1)^(1/2) - n] [(n^2+1)^(1/2) +n] / [(n^2+1)^(1/2) + n]
= [n^2+1-n^2 ]/ [(n^2+1)^(1/2) + n]
= 1/[(n^2+1)^(1/2) + n]
lim
所以 lim
lim
答
这个极限应该发散吧,n趋于无穷时(n^2+1)^(1/2)也趋向于无穷,但lim sin pi x
答
等于0