这极限怎么求 我需要具体的步骤
2个回答
展开全部
lim(x->∞) (2x-1)^2.(x+1)/(3x^3+x^2 -1)
=lim(x->∞) (2-1/x)^2.(1+1/x)/(3+1/x -1/x^2)
=4/3
let
1/y = 1/(3x)
lim(x->∞) ( 1- 1/(3x))^x
=lim(y->∞) ( 1- 1/y )^(y/3)
=e^(-1/3)
=>
lim(x->∞) [ (2x-1)^2.(x+1)/(3x^3+x^2 -1) - ( 1- 1/(3x))^x ]
=4/3 -e^(-1/3)
=lim(x->∞) (2-1/x)^2.(1+1/x)/(3+1/x -1/x^2)
=4/3
let
1/y = 1/(3x)
lim(x->∞) ( 1- 1/(3x))^x
=lim(y->∞) ( 1- 1/y )^(y/3)
=e^(-1/3)
=>
lim(x->∞) [ (2x-1)^2.(x+1)/(3x^3+x^2 -1) - ( 1- 1/(3x))^x ]
=4/3 -e^(-1/3)
已赞过
已踩过<
评论
收起
你对这个回答的评价是?
推荐律师服务:
若未解决您的问题,请您详细描述您的问题,通过百度律临进行免费专业咨询