高数极限题

2025-02-10 05:51:39
推荐回答(5个)
回答1:

望采纳,关键是分子分母趋于0的元素消掉

回答2:

这个题考一个公式,当然也可以用洛必达法则做

回答3:

回答4:

用罗必塔法则得

原式 = lim-(1/2)x^(-1/2)/[-(1/3)x^(-2/3)
= lim3x^(1/6)/2 = 3/2

回答5:

1-x^(1/2) = 1^3- [x^(1/6)]^3 = [1-x^(1/6)]. [ 1+x^(1/6) +x^(1/3) ]
1-x^(1/3) = 1^2- [x^(1/6)]^2 = [1-x^(1/6)]. [ 1+x^(1/6) ]
lim(x->1) [1-x^(1/2) ]/[1-x^(1/3) ]
=lim(x->1) [1-x^(1/6)]. [ 1+x^(1/6) +x^(1/3) ]/ { [1-x^(1/6)]. [ 1+x^(1/6)] }
=lim(x->1) [ 1+x^(1/6) +x^(1/3) ]/ [ 1+x^(1/6)]
=3/2